WO2014085030A2

WO2014085030A2 - Apparatus and method of delivering a fluid using direct proppant injection

Info

Publication number: WO2014085030A2
Application number: PCT/US2013/068267
Authority: WO
Inventors: Stephen Duane Sanborn; Jason Paul Mortzheim; Tiffany Elizabeth Pinard Westendorf
Original assignee: General Electric Company
Priority date: 2012-11-30
Filing date: 2013-11-04
Publication date: 2014-06-05
Also published as: CN104937210A; US20140151049A1; AU2013353386B9; AU2013353386A1; AU2013353386B2; WO2014085030A3

Abstract

An apparatus and method for delivering a fluid mixture using direct injection to a mixing apparatus. The apparatus including a proppant storage vessel configured to contain therein a proppant material and output a proppant output flow at ambient pressure to a solid feed pump assembly. The apparatus further including a fracturing fluid storage vessel configured to contain therein a fracturing fluid and output a fracturing fluid output flow at a fracture fluid blending pressure. The solid feed pump assembly configured to output to a mixing apparatus, a proppant output flow at the fracture fluid blending pressure. The mixing apparatus configured to output a fluid mixture of the proppant and the fracturing fluid at the fracture fluid blending pressure. The mixing apparatus coupled to a high pressure pump assembly and configured to deliver the fluid mixture therein to a downstream component at an injection pressure.

Description

APPARATUS AND METHOD OF DELIVERING A FLUID

USING DIRECT PROPPANT INJECTION

BACKGROUND

[0001] Embodiments disclosed herein relate generally to an apparatus and method of delivering a fluid mixture into a wellbore.

[0002] Hydraulic fracturing, commonly known as hydrofracking, or simply fracking, is a technique used to release petroleum, natural gas or other substances for extraction from underground reservoir rock formations. A wellbore is drilled into the reservoir rock formation, and a treatment fluid is pumped which causes fractures and allows for the release of trapped substances produced from these subterranean natural reservoirs. Current wellhead fracking systems utilize a process wherein a slurry of fracturing fluid and proppant (e.g. sand) is created and then pumped into the well at high pressure. When water-based fracturing fluids are used, the proppant, water and appropriate chemicals can be mixed at atmospheric pressure and then pumped up to a higher pressure for injection into the well. However, if fluids other than water (e.g. liquid CO₂ or liquid propane) are used as the fracturing fluid, then these fluids must be kept at a sufficient pressure throughout the hydraulic fracturing system to avoid undesired vaporization. As a result, the blending of these fluids with proppant, chemicals, etc. must also be accomplished while the fluids are kept under a sufficiently high pressure. Current pressurized blenders exist for this purpose.

[0003] Known pressurized blenders capable of blending these vaporizing fracturing fluids with the proppant at a suitably high pressure utilize a pressurized proppant storage vessel arrangement to feed and meter the proppant into the pressurized fracturing fluid. These known lock-hopper based pressurized blenders require preloading with the proppant to be utilized during a given fracture stage. The pressurized proppant storage vessels used typically have a capacity in the range of 20-40 tons of proppant (e.g., sand). The limited volume capacity of the proppant storage vessel system provides for limited amounts of proppant to be blended with the fracturing fluid. If the fracturing design requires more sand, then multiple blenders must be used. In addition, these known pressurized blenders require an undesirably long elapsed time to reload them with proppant for the next fracture stage. In some instances, some pressurized blender operations require the blender unit be moved off-site to another location for the purpose of reloading with proppant, also requiring an undesirably long time and potentially adding to the truck traffic associated with fracturing operations. In many instances, the limited capacity requires specialized logistics and on-pad (or off-pad) proppant handling equipment to be used in conjunction with the proppant storage vessel based pressurized blenders.

[0004] Accordingly, there is a need for an improved pumping system and method for delivering treatment fluid into a wellbore that will enable the blending and pumping of essentially unlimited quantities of proppant and fracturing fluid to form the fluid mixture. The ability to deliver unlimited quantities will provide for continuous operation of the pressurized blender and sand feeding equipment, enable fracture plans to be based upon reservoir stimulation requirements without imposing equipment constraints, and therefore providing overall a more efficient system.

BRIEF SUMMARY

[0005] These and other shortcomings of the prior art are addressed by the present disclosure, which provides an apparatus and method of delivering a fluid using direct proppant injection to a pressurized blender.

[0006] In accordance with an embodiment, provided is an apparatus for delivering a fluid mixture comprising: a proppant storage vessel, a solid feed pump assembly, a fracturing fluid storage vessel, a mixing apparatus and a high pressure pump assembly. The proppant storage vessel is configured to contain therein a proppant material and output a proppant output flow at ambient pressure. The solid feed pump assembly is coupled to the proppant storage vessel. The solid feed pump assembly including a proppant inlet in fluidic communication with the proppant storage vessel proppant output flow. The solid feed pump assembly is configured to output a proppant output flow at or above a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. The fracturing fluid storage vessel is configured to contain therein a fracturing fluid and output a fracturing fluid output flow at the fracture fluid blending pressure. The mixing apparatus is coupled to the solid feed pump assembly. The mixing apparatus including a proppant inlet in fluidic communication with the solid feed pump assembly proppant output flow and a fracturing fluid inlet in fluidic communication with the fracturing fluid output flow. The mixing apparatus is configured to mix the proppant output flow and the fracturing fluid output flow therein and output a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure. The high pressure pump assembly is coupled to the mixing chamber and configured to deliver the fluid mixture therein to a downstream component at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

[0007] In accordance with another embodiment, provided is an apparatus for delivering a fluid mixture comprising: a proppant storage vessel, a solid feed pump assembly, wherein the solid feed pump assembly is one of a Posimetric® pump assembly, an eductor pump assembly or a rotary positive displacement pump assembly, a fracturing fluid storage vessel, a mixing apparatus and a high pressure pump assembly. The proppant storage vessel is configured to contain therein a proppant material and output a proppant output flow at ambient pressure. The solid feed pump assembly is coupled to the proppant storage vessel and including a proppant inlet in fluidic communication with the proppant storage vessel proppant output flow. The solid feed pump assembly is configured to output a proppant output flow at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. The fracturing fluid storage vessel is configured to contain therein a fracturing fluid and output a fracturing fluid output flow at the fracture fluid blending pressure. The mixing apparatus is coupled to the solid feed pump assembly and including a proppant inlet in fluidic communication with the solid feed pump assembly proppant output flow and a fracturing fluid inlet in fluidic communication with the fracturing fluid output flow. The mixing apparatus is configured to mix the proppant output flow and the fracturing fluid output flow therein and output a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure. The high pressure pump assembly is coupled to the mixing chamber and configured to deliver the fluid mixture therein to a downstream component at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure. [0008] In accordance with yet another embodiment, provided is a method for delivering a fluid mixture, comprising: providing an input of a proppant material at ambient pressure to a proppant storage vessel, the proppant storage vessel configured to output a proppant output flow at ambient pressure; providing an input of a fracture fluid at a fracture fluid blending pressure to a fracture fluid storage vessel, the fracture fluid storage vessel configured to output a fracture fluid output flow at the fracture fluid blending pressure; inputting the proppant output flow at ambient pressure from the proppant storage vessel into a solid feed pump assembly wherein the pressure of the proppant output flow is increased to a fracture blending pressure; inputting the proppant output flow at the fracture fluid blending pressure and a fracture fluid output flow at a fracture fluid blending pressure into a mixing apparatus; mixing the proppant output flow and the fracturing fluid output flow therein the mixing apparatus and outputting a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure; increasing the pressure of the output fluid mixture in a high pressure pump; and delivering the high pressure fluid mixture to one or more downstream

components.

[0009] Other objects and advantages of the present disclosure will become apparent upon reading the following detailed description and the appended claims with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

[0010] The above and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein

[0011] FIG. 1 is a schematic diagram of an apparatus for delivering a fluid mixture using a solid feed pump assembly for direct proppant injection to a pressurized mixing apparatus constructed in accordance with an embodiment; [0012] FIG. 2 is a schematic diagram of an apparatus for delivering a fluid mixture using a Posimetric® pump assembly for direct proppant injection to a pressurized mixing apparatus constructed in accordance with another embodiment;

[0013] FIG. 3 is a schematic diagram of an apparatus for delivering a fluid mixture using a eductor pump assembly direct proppant injection to a pressurized mixing apparatus constructed in accordance with still another embodiment;

[0014] FIG. 4 is a schematic diagram of an apparatus for delivering a fluid mixture using a pressurized rotary positive displacement pump assembly for direct proppant injection to a pressurized mixing apparatus constructed in accordance with still another embodiment; and

[0015] FIG. 5 is a schematic block diagram of a method of delivering a fluid mixture using a direct proppant injection to a pressurized mixing apparatus constructed in accordance with still another embodiment.

DETAILED DESCRIPTION

[0016] This disclosure will be described for the purposes of illustration only in connection with certain embodiments; however, it is to be understood that other objects and advantages of the present disclosure will be made apparent by the following description of the drawings according to the disclosure. While preferred embodiments are disclosed, they are not intended to be limiting. Rather, the general principles set forth herein are considered to be merely illustrative of the scope of the present disclosure and it is to be further understood that numerous changes may be made without straying from the scope of the present disclosure.

[0017] Preferred embodiments of the present disclosure are illustrated in the figures with like numerals being used to refer to like and corresponding parts of the various drawings. It is also understood that terms such as "top", "bottom", "outward", "inward", and the like are words of convenience and are not to be construed as limiting terms. It is to be noted that the terms "first," "second," and the like, as used herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. The modifier "about" used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity).

[0018] As used herein, the process of forming of a fluid mixture includes mixing a fluid with a powdered or particulate material, such as proppant, a powdered dissolvable or a hydratable additive (prior to hydration). In a continuous treatment or in a continuous part of a well treatment, the fluids are handled as fluid streams.

[0019] Referring to the drawings wherein, as previously stated, identical reference numerals denote the same elements throughout the various views, FIG. 1 depicts in a simplified block diagram, elements of an apparatus for delivering a fluid mixture 100 including direct proppant injection to a pressurized blender, or mixing apparatus, according to an embodiment. The apparatus 100 includes a proppant storage vessel 102 coupled to a solid feed pump assembly 104. The proppant storage vessel 102 is coupled to the solid feed pump assembly 104, at an inlet port 106 of the solid feed pump assembly 104. More specifically, an outlet 108 of the proppant storage vessel 102 is configured in fluidic communication with the inlet 106 of the solid feed pump assembly 104. The proppant storage vessel 102 is configured as a traditional unpressurized storage type vessel and includes a body 1 10 configured to hold a proppant material 112 therein at atmospheric pressure. The proppant storage vessel 102 may further include a proppant material inlet 114 coupled to a proppant material loading device 116 and a source of proppant material (not shown). In an embodiment, the proppant material 112 may be comprised of a sand, or other material commonly utilized as proppant in pumping operations. The proppant storage vessel 102 provides adequate storage and loading capabilities to allow for a continuous supply of proppant material 1 12 to solid feed pump assembly 104. [0020] During operation, the proppant storage vessel 102 may be loaded by the material loading device 116, such as a screw auger, conveyor, or any other low pressure means configured to move the proppant material 1 12 from a proppant supply source (not shown) to the proppant storage vessel 102. Alternate means for providing the proppant material 1 12 to the proppant storage vessel 102 are anticipated herein.

[0021] The solid feed pump assembly 104 includes a pump assembly capable of receiving a proppant output flow 1 18 at atmospheric pressure via outlet 108 and inlet 106 and then providing at solid feed pump assembly outlet 120, a proppant output flow 122 at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. In an embodiment, the fracture fluid blending pressure is in a range of about 50 psi to 400 psi, and preferably at a pressure of approximately 300 psi.

\

[0022] A pressurized blender, or mixing apparatus, 124 is configured to receive the proppant output flow 122 via a proppant inlet 126. A fracturing fluid storage vessel 128 is provided in fluidic communication via an outlet 130 with the pressurized mixing apparatus 124 via a fracturing fluid inlet 132. The fracturing fluid storage vessel 128 is configured for storage of a fracturing fluid 134 at a required temperature and storage pressure, and more particularly at or above the fracture blending pressure. The pressurized mixing apparatus 124 is configured to receive a fracturing fluid output flow 136 at the fracture fluid blending pressure via the inlet 132. In an embodiment, the fracturing fluid storage vessel 128 is configured to permit a minimal amount of the fracturing fluid output flow 136 to enter the solid feed pump assembly 104 so as to provide for moistening of the proppant material to accomplish pumping therethrough of the proppant material 1 12. It should be understood that while anticipated is the permitting of a minimal amount of fracturing fluid output flow 136 to enter the solid feed pump assembly 104, in contrast to previous known pumping systems, the amount of fracturing fluid output flow 136 that is allowed to enter the solid feed pump assembly 104 is not sufficient to provide for the formation of a dense proppant/fluid slurry to be pumped through the pump assembly 104.

[0023] During operation, the proppant output flow 122 and the fracturing fluid output flow 136 are blended, or mixed, within the pressurized mixing apparatus 124 and delivered as a fluid mixture output flow 138 via an outlet 140 of the pressurized mixing apparatus 124 to a high pressure pump assembly 142. In alternate

embodiments, a fracture fluid booster pump 141 may be provided inline between the mixing apparatus 124 and the high pressure pump assembly 142, or alternatively provided as part of the functionality of the high pressure pump assembly 142. The fluid mixture output flow 138 is output at the fracture blending pressure. The fluid mixture output flow 138 is received via a fluid mixture inlet 144 of the high pressure pump assembly 142. The high pressure pump assembly 142 is configured to deliver the fluid mixture output flow 138 received therein to a downstream component 146 at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure. More specifically, in an embodiment, the high pressure pump assembly 142 is configured to deliver a high pressure fluid mixture output flow 148 via an outlet 150 of the high pressure pump assembly 142 to an inlet 152 of the downstream component 146, such as a well head 154.

[0024] The inclusion of the solid feed pump assembly 104 in apparatus 100 will allow unlimited amounts of the proppant material 1 12 to be blended with the fracture fluid 134, using conventional sand logistics and on-pad handling equipment.

Accordingly, the solid feed pump assembly 104 is capable of operating continuously, in contrast to semi-batch operating modes of the state of the art lock hoppers.

[0025] Further embodiments of an apparatus for delivering a fluid using direct injection of a proppant at ambient pressure to a pressurized blender are illustrated in FIGs. 2-4. More particularly, illustrated are alternate embodiments of the solid feed pump assembly 104 as described in FIG. 1. Each of the embodiments of FIGs. 2-4 addresses the direct delivery of a dry proppant material, such as proppant material 112 of FIG. 1, to a pump assembly for pressurization and subsequent mixing with the fracture fluid 134 in a pressurized mixing apparatus 124. More particularly, each of the embodiments of FIGs. 2-4 describes a pump assembly that may be utilized for the solid feed pump assembly 104, as described in FIG. 1. Accordingly, like numbers are used to identify like elements throughout the described embodiments and in an effort to provide a concise description of these embodiments, like features and elements previously described will not be further described. [0026] Referring more specifically to FIG. 2, illustrated is an embodiment of an apparatus for delivering a fluid mixture, generally referenced 200. The apparatus 200 includes a proppant storage vessel 102 configured to contain therein a proppant material 1 12 and output a proppant output flow 1 18 at ambient pressure. A solid feed pump assembly 104 is provided and coupled to the proppant storage vessel 102. The solid feed pump assembly 104 includes a proppant inlet 106 in fluidic communication with the proppant storage vessel proppant output flow 1 18. In this particular embodiment, the solid feed pump assembly 104 is a Posimetric® pump assembly 202. The Posimetric® pump assembly 202 employs positive-displacement action to feed the proppant material 112 into the pressurized blender without the need for a pressurizing fluid. The Posimetric® pump assembly 202 does not employ screws, augers, belts or vibratory trays to convey the proppant material 112, and in contrast employs at least one vertical rotating spool 204 disposed within a pump body 208 to move the proppant material 112 therein. The proppant output flow 1 18 is initially input at an input duct 206 that is coupled to the pump body 208. As the proppant output flow 118 enters and fills the pump assembly 202, and more particularly the pump body 208, from above, the material locks itself firmly into the confines of the rotating spool 204 contained therein, which carries it through an arc of approximately 180°. More particularly, the proppant output flow 1 18 is rotated within the rotating spool 204, housed within the pump body 208, where it becomes "locked up" or compacted so as to act as a solid mass, and discharged via an output duct 210 at the outlet 120 as a proppant output flow 122. While within the pump body 208, the proppant material 118 acts as a solid mass and a seal against the high pressure outlet. At the time of discharge via the outlet 120, the proppant material output flow 122 is output at an increased pressure, and more particularly at a fracture blending pressure that is higher than ambient pressure.

[0027] In a preferred embodiment, the Posimetric® pump assembly 202 includes a consolidation section 212, a rotating section 214 and a discharge section 216. During operation, the proppant material 112 enters the pump assembly 202 and becomes consolidated as the individual proppant material particles settle and come into contact with each other as well as the sidewalls defining the pump body 208, the particles become compacted and act as a solid mass and form a seal against the high pressure outlet environment. As the proppant material 112 rotates in the rotating spool 204 and pump body 208, the pressure of the proppant material 112 is increased to the fracture blending pressure. Discharge of the proppant material 112 at the increased fracture blending pressure occurs upon rotating of the rotating spool 204 to the outlet 120. Exemplary pump assemblies are described in commonly assigned U.S. Patent No. 8,006,827, D. Aldred et ah, "Transporting Particulate Material", issued August 3, 201 1, which is incorporated by reference herein in its entirety.

[0028] The Posimetric® pump assembly 202 is configured to output the proppant output flow 122 at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. The apparatus 200 further includes a fracturing fluid storage vessel 128 configured to contain therein a fracturing fluid 134 and output a fracturing fluid output flow 136 at or above the fracture fluid blending pressure. A pressurized blender, or mixing apparatus, 124 is coupled to the Posimetric® pump assembly 202 to receive the discharged proppant output flow 122 therefrom and to the fracturing fluid storage vessel 128. The mixing apparatus 124 is configured to mix the proppant output flow 122 and the fracturing fluid output flow 136 therein and output a fluid mixture 138 of proppant and fracturing fluid at the fracture fluid blending pressure. A fracturing fluid booster pump 141 and a high pressure pump assembly 142 are coupled to the mixing apparatus 124 and configured to deliver a high pressure fluid mixture 148 therein to a downstream component 146 at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

[0029] Referring more specifically to FIG. 3, illustrated is another embodiment of an apparatus for delivering a fluid mixture, generally referenced 300. The apparatus 300 includes a proppant storage vessel 102 configured to contain therein a proppant material 1 12 and output a proppant output flow 1 18 at ambient pressure. The apparatus 300 further includes a fracturing fluid storage vessel 128 configured to contain therein a fracturing fluid 134 and output a fracturing fluid output flow 136 at or above a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure as previously described. A solid feed pump assembly 104 is provided and coupled to the proppant storage vessel 102 and the fracturing fluid storage vessel 128. The solid feed pump assembly 104 includes a proppant inlet 106 in fluidic communication with the proppant storage vessel proppant output flow 118 and a fracture fluid inlet 324 in fluidic communication with at least a portion of the fracturing fluid output flow 136. In this particular embodiment, the solid feed pump assembly 104 is an eductor pump assembly 302. During operation, the eductor pump assembly 302 employs the Venturi effect of a converging-diverging nozzle to convert the pressure energy of a motive fluid, and more particularly a portion of the fracturing fluid output flow 136, to velocity energy to feed the proppant material 1 12. Similar to the previously described Posimetric® pump assembly 202, the eductor pump assembly 302 does not employ screws, augers, belts or vibratory trays to convey the proppant material 1 12 within the pump assembly toward the downstream components.

[0030] As illustrated in FIG. 3, the proppant output flow 118 is initially input into the eductor pump assembly 302 via an input duct 306 that is coupled to a pump body 308. The input of the proppant storage vessel proppant output flow 118 may be metered by a valve mechanism (not shown) disposed in the input duct 306. In an embodiment, the eductor pump assembly 302 further includes a first converging nozzle 310, a second converging nozzle 312, a mixing chamber 314 and a diffuser, or expansion feature, 316.

[0031] In an embodiment, the eductor pump assembly 302 includes the eductor body 308, and more particularly a suction chamber 318 that is driven by the motive fluid, and more particularly at least a portion of the fracturing fluid output flow 136 utilized as a motive flow. In an embodiment, at least a portion of the fracturing fluid output flow 136 is input directly into the mixing apparatus 124. The fracturing fluid output flow 136 is accelerated through the first converging nozzle 310. As with traditional eductors, accelerating a higher pressure fluid through the first converging nozzle 310 drops the static pressure of a motive flow exiting through the first converging nozzle 310, while simultaneously decreasing the static pressure within the suction chamber 318. The lower suction pressure in the suction chamber 318 draws in the proppant output flow 118, as a suction flow via the inlet port 106 of the eductor pump assembly 302. Subsequently, a fluid mixture 320, comprised of a combination of the proppant output flow 1 18 and the fracturing fluid output flow 136, is delivered to the second converging nozzle 312 prior to reaching the mixing chamber 314.

Within the mixing chamber 314 the fluid mixture 320, comprised of the proppant output flow 1 18 and the fracturing fluid output flow 136, is further mixed as the stratifications between the two fluids is allowed to settle out and as the turbulent fluid structure is reduced. The fluid mixture 320 exiting the mixing chamber 314 is expanded in the expansion feature 316, prior to being delivered to the downstream components that may ultimately be in fluidic communication with a wellhead. The expansion feature 316 provides an expansion of the fluid mixture 320 and provides a decrease in the velocity of the fluid mixture 320 and recovery of the pressure of the fluid mixture 320 allowing the fluid to be delivered to a mixing apparatus 124 at a fracture blending pressure.

[0032] During operation of the apparatus 300, including the eductor pump assembly 302, the eductor pump assembly 302 is placed in operation by pressurizing the suction chamber 318. Subsequent to the appropriate pressure condition being reached, an optional valve mechanism or gate, 322, disposed between the proppant storage vessel 102 and the inlet port 106 may be opened to allow the proppant storage vessel 102 contents to enter the eductor pump assembly 302, and more particularly the suction chamber 318. The suction chamber 318 draws in the proppant output flow 1 18, including the proppant material 1 12, as the suction flow, and subsequently mixes with the motive flow, and more particularly, at least a portion of the fracturing fluid output flow 136. Operation of the apparatus may be continuous with continuous flow of the proppant output flow 1 18 and the fracturing fluid output flow 136.

[0033] It should be noted that valve mechanism 322 is optional, being required in an application where the desire is to allow the eductor pump assembly 302 to remain at full pressure. As valves in the direct path of the proppant output flow 118, and more particularly proppant material 1 12, it will be subject to a harsh abrasive environment, it is realized that valve mechanism 322 will be subject to higher wear rates. As such, an embodiment eliminating the valve mechanism 322 is anticipated.

[0034] The eductor pump assembly 302 is configured to output a proppant output flow 122 at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. The apparatus 300 further includes a pressurized blender, or mixing apparatus, 124 coupled to the eductor pump assembly 302 to receive the discharged proppant output flow 122 therefrom and the fracturing fluid output flow 136. The mixing apparatus is configured to mix the proppant output flow 122 and the fracturing fluid output flow 136 therein and output a fluid mixture output flow 138 of proppant and fracturing fluid at the fracture fluid blending pressure. A fracturing fluid booster pump 141 and a high pressure pump assembly 142 are coupled to the mixing apparatus 124 and configured to deliver the fluid mixture 138 therein to a downstream component 146 as a high pressure fluid mixture output flow 148 at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

[0035] Accordingly, the inclusion of the eductor pump assembly 302, as described in apparatus 300, provides for the pressurizing of the fracturing fluid 134 in a conventional high pressure fluid pump and then use that at least a portion of the flow of high-pressure fracturing fluid 136 as the motive fluid flow through the eductor pump assembly 302 to convey the proppant 112 and more particularly the proppant output flow 118 into the flowing motive fluid.

[0036] Referring more specifically to FIG. 4, illustrated is another embodiment of an apparatus for delivering a fluid mixture, generally referenced 400. The apparatus 400 includes a proppant storage vessel 102 configured to contain therein a proppant material 1 12 and output a proppant output flow 1 18 at ambient pressure. The apparatus 400 further includes a fracturing fluid storage vessel 128 configured to contain therein a fracturing fluid 134 and output a fracturing fluid output flow 136 at or above a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure as previously described. A solid feed pump assembly 104 is provided and coupled to the proppant storage vessel 102 and the fracturing fluid storage vessel 128. The solid feed pump assembly 104 includes a proppant inlet 106 in fluidic communication with the proppant storage vessel proppant output flow 118. In this particular embodiment, the solid feed pump assembly 104 is positive displacement pump, and more particularly a rotary-type posititive displacement pump, such as an internal gear, screw or auger type pump assembly, referenced 402. The unique design of the positive displacement pump 402, ensures that the proppant material 1 12 is constantly present at a feed inlet 404, while the controlled rotation of a feed mechanism 406 moves the proppant material 112. and more particulalry the proppant output flow 1 18, from the feed inlet 404 to a discharge point 408. In the illustrated embodiment, the feed mechanism 406 comprises a screw mechanism 410 (a helical surface surrounding a central cylindrical shaft) disposed inside a hollow body 412.

[0037] As illustrated in FIG. 4, the proppant output flow 118 is initially input into the rotary-type positive displacement pump 402 via the feed inlet 404. Similar to the previous embodiment, the input of the proppant storage vessel proppant output flow 118 may be metered by an optional valve mechanism (not shown). Similar to the Posimetric® pump assembly 202 of FIG. 1, the positive displacement pump assembly 402 employs positive-displacement action to feed the proppant material 1 12 as a free- flowing material with a uniform discharge in a linear volumetric fashion. In contrast to the Posimetric® pump assembly 202, the positive displacement pump assembly 402 employs screws, augers, belts or vibratory trays to convey the proppant material 1 12 therein. The proppant output flow 118 is initially input at the feed inlet 404 that is coupled to the pump body 412. As the proppant output flow 1 18 enters and fills the pump assembly 402, and more particularly the pump body 412, the material is carried by the feed mechanism 406 contained therein, toward the discharge point 408. The proppant output flow 1 18 is rotated within the feed mechanism 406, housed within the pump body 412 and discharged via an output duct 414 at the discharge point 408 as a proppant output flow 122. At the time of discharge via an outlet 120, the proppant material output flow 122 is output at an increased pressure, and more particularly at a fracture blending pressure that is higher than ambient pressure.

[0038] In a preferred embodiment, during operation, the proppant material 1 12 enters the rotary-type positive displacement pump 402 at the feed inlet 404. As the proppant material 112 rotates in the feed mechanism 410 and pump body 412, the pressure of the proppant material 112 is increased to the fracture blending pressure. Discharge of the proppant material 112 at the increased fracture blending pressure occurs upon rotation of the feed mechanism 406 to the outlet 120.

[0039] The rotary-type positive displacement pump 402 is configured to output the proppant output flow 122 at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure. The apparatus 400 further includes a pressurized blender, or mixing apparatus, 124 coupled to the rotary-type positive displacement pump 402 to receive the discharged proppant output flow 122 therefrom and the fracturing fluid output flow 136. The mixing apparatus 124 is configured to mix the proppant output flow 122 and the fracturing fluid output flow 134 therein and output a fluid mixture 138 of proppant material 1 12 and fracturing fluid 134 at the fracture fluid blending pressure. A high pressure pump assembly 142 coupled to the mixing chamber 124 is configured to deliver a high pressure fluid mixture 148 to a downstream component 146 at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure. In this particular embodiment, a separate booster pump is not provided, and in in lieu of boosting of the fracturing fluid pressure is provided as part of the functionality of the high pressure pump assembly 142.

[0040] Accordingly, the inclusion of the rotary-type positive displacement pump 402, as described in apparatus 400, provides for the pressurizing of the fracturing fluid 134 in a conventional high pressure fluid pump. The proppant 1 12 does not flow through a conventional high pressure fluid pump, or pumps, thereby minimizing degradation to these pumps that pumping the proppant 112 through them would cause.

[0041] FIG. 5 is a schematic block diagram of a method 500 of delivering a fluid mixture using direct proppant injection to a pressurized blender using a solid feed pump assembly in an apparatus 100, 200, 300 according to an embodiment disclosed herein. Generally, the method involves providing an input of a proppant material 1 12 to a proppant storage vessel 102, and providing an input of a fracture fluid 134 to a fracture fluid storage vessel 128, at a step 502. Next in step 504, a proppant output flow 1 18 at ambient pressure from the proppant storage vessel 102 is input into a solid feed pump assembly 104. As previously described, the solid feed pump assembly 104 may be configured as a positive displacement pump assembly, and more particularly a Posimetric® pump assembly 202 (as best illustrated in FIG. 2) or a rotary-type positive displacement pump 402 (as best illustrated in FIG. 4) or as an eductor pump assembly 304 (as best illustrated in FIG. 3). Next in step 506, the proppant output flow 1 18 and a fracturing fluid output flow 136 are input to a mixing apparatus 124. In an embodiment, the fracturing fluid output flow 136 is input to the mixing apparatus 124 via an eductor pump assembly. The mixing apparatus 124 is configured to mix the proppant output flow 118 and the fracturing fluid output flow 136 therein and output a fluid mixture output flow 138 of the proppant and fracturing fluid at the fracture fluid blending pressure, at step 508. The pressure of the fluid mixture output flow 138 is next increased in a high pressure pump 142, at step 510. Subsequently the high pressure fluid mixture 148 is delivered to one or more downstream components 146, at a step 512, and ultimately may include delivery to a well head.

[0042] Additional commercial advantages of the disclosed apparatus are related to the current problem faced in unconventional gas development and the requirement to mix/blend chemicals and a proppant, namely sand with fracturing fluids (e.g., liquid CO₂, liquid propane gas) that require they always be contained at a suitable fracture fluid blending pressure to avoid vaporization of these fracturing fluids. Accordingly, disclosed is apparatus and method of delivering a fluid mixture using a solid feed pump assembly and direct proppant injection into a pressurized mixing apparatus in such a way that a continuous flow of proppant can be provided without being constrained by the total volume limits of the known lock hopper based approaches.

[0043] The foregoing has described an apparatus and method of delivering a fluid mixture using direct injection of a proppant into a pressurized mixing apparatus. While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. While the present disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the disclosure. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

Claims

CLAIMS:

1. An apparatus for delivering a fluid mixture comprising:

a proppant storage vessel configured to contain therein a proppant material and output a proppant output flow at ambient pressure;

a solid feed pump assembly coupled to the proppant storage vessel, the solid feed pump assembly including a proppant inlet in fluidic communication with the proppant storage vessel proppant output flow, the solid feed pump assembly configured to output a proppant output flow at or above a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure;

a fracturing fluid storage vessel configured to contain therein a fracturing fluid and output a fracturing fluid output flow at the fracture fluid blending pressure;

a mixing apparatus coupled to the solid feed pump assembly, the mixing apparatus including a proppant inlet in fluidic communication with the solid feed pump assembly proppant output flow and a fracturing fluid inlet in fluidic communication with the fracturing fluid output flow, the mixing apparatus configured to mix the proppant output flow and the fracturing fluid output flow therein and output a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure; and a high pressure pump assembly coupled to the mixing chamber and configured to deliver the fluid mixture therein to a downstream component at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

2. The apparatus of Claim 1, wherein the solid feed pump assembly is a Posimetric® pump assembly.

3. The apparatus of Claim 1, wherein the solid feed pump assembly is an eductor pump assembly.

4. The apparatus of Claim 1, wherein the solid feed pump assembly is a rotary positive displacement pump assembly.

5. The apparatus of Claim 1, wherein the fracture fluid blending pressure is in a range of 200-400 psi.

6. The apparatus of Claim 5, wherein the fracture fluid blending pressure is approximately 300 psi.

7. The apparatus of Claim 1, wherein the injection pressure is in a range of 5000-12,000 psi or higher.

8. The apparatus of Claim 1, wherein the injection pressure is

approximately 10,000 psi.

9. The apparatus of Claim 1 , wherein the proppant material is sand.

10. The apparatus of Claim 1, wherein the fracturing fluid is at least one of liquid CO₂ or liquid propane.

11. The apparatus of Claim 1 , wherein the solid feed pump assembly is configured to receive a continual supply of proppant material and output a continuous proppant output flow.

12. An apparatus for delivering a fluid mixture comprising:

a solid feed pump assembly coupled to the proppant storage vessel, the solid feed pump assembly including a proppant inlet in fluidic communication with the proppant storage vessel proppant output flow, the solid feed pump assembly configured to output a proppant output flow at a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure, wherein the solid feed pump assembly is one of a Posimetric® pump assembly, an eductor pump assembly or a rotary positive displacement pump assembly;

a fracturing fluid storage vessel configured to contain therein a fracturing fluid and output a fracturing fluid output flow at the fracture fluid blending pressure; a mixing apparatus coupled to the solid feed pump assembly, the mixing apparatus including a proppant inlet in fluidic communication with the solid feed pump assembly proppant output flow and a fracturing fluid inlet in fluidic communication with the fracturing fluid output flow, the mixing apparatus configured to mix the proppant output flow and the fracturing fluid output flow therein and output a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure; and a high pressure pump assembly coupled to the mixing chamber and configured to deliver the fluid mixture therein to a downstream component at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

13. The apparatus of Claim 12, wherein the fracture fluid blending pressure is in a range of 200-400 psi.

14. The apparatus of Claim 13, wherein the fracture fluid blending pressure is approximately 300 psi.

15. The apparatus of Claim 12, wherein the injection pressure is in a range of 5000-12,000 psi.

16. The apparatus of Claim 12, wherein the proppant material is sand and the fracturing fluid is at least one of liquid CO₂ or liquid propane.

17. The apparatus of Claim 12, wherein the solid feed pump assembly is a Posimetric® pump assembly coupled to the proppant storage vessel, the Posimetric® pump assembly comprising:

a consolidation section configured to cause the proppant material to compact and act as a solid mass;

a rotating section configured to increase the pressure of the proppant material therein to the fracture blending pressure; and

a discharge section configured to discharge the proppant material at the increased fracture blending pressure.

18. The apparatus of Claim 12, wherein the solid feed pump assembly is an eductor pump assembly coupled to the proppant storage vessel and the fracturing fluid storage vessel, the eductor pump assembly comprising:

a suction chamber in fluidic communication with the proppant output flow, the fracture fluid output flow and a motive fluid flow, the suction chamber configured to output a fluid mixture to a mixing chamber; and

an expansion feature coupled to the mixing chamber and configured to expand the fluid mixture therein for delivery to a downstream component.

19. The apparatus of Claim 12, wherein the solid feed pump assembly is rotary positive displacement pump assembly coupled to the proppant storage vessel, the rotary positive displacement pump assembly comprising:

a pump body, including a feed inlet at a first end and a discharge point at a second end;

a feed mechanism disposed wtihin the pump body and configured to move the proppant material from the feed inlet to the discharge point while increasing a pressure of the proppant material from an ambient pressure to a fracture blending pressure.

20. An apparatus for delivering a fluid mixture comprising:

a proppant storage vessel configured to output a proppant output flow at ambient pressure;

a solid feed pump in fluidic communication with the proppant storage vessel, the solid feed pump assembly configured to output a proppant output flow at or above a fracture fluid blending pressure, wherein the fracture fluid blending pressure is greater than the ambient pressure;

a fracturing fluid storage vessel configured to contain therein a fracturing fluid at the fracture fluid blending pressure;

a mixing apparatus coupled to the solid feed pump assembly and the fracturing fluid storage vessel, the mixing apparatus configured to output a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure; and

a high pressure pump assembly coupled to the mixing chamber and configured to output a fluid mixture to a downstream component at an injection pressure, wherein the injection pressure is greater than the fracture fluid blending pressure.

21. A method of delivering a fluid mixture, comprising:

providing an input of a proppant material at ambient pressure to a proppant storage vessel, the proppant storage vessel configured to output a proppant output flow at ambient pressure;

providing an input of a fracture fluid at a fracture fluid blending pressure to a fracture fluid storage vessel, the fracture fluid storage vessel configured to output a fracture fluid output flow at the fracture fluid blending pressure;

inputting the proppant output flow at ambient pressure from the proppant storage vessel into a solid feed pump assembly wherein the pressure of the proppant output flow is increased to a fracture blending pressure;

inputting the proppant output flow at the fracture fluid blending pressure and a fracture fluid output flow at a fracture fluid blending pressure into a mixing apparatus; mixing the proppant output flow and the fracturing fluid output flow therein the mixing apparatus and outputting a fluid mixture of proppant and fracturing fluid at the fracture fluid blending pressure;

increasing the pressure of the output fluid mixture in a high pressure pump; and delivering the high pressure fluid mixture to one or more downstream components.