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Publication numberUS2191121 A
Publication typeGrant
Publication dateFeb 20, 1940
Filing dateJan 5, 1940
Priority dateMar 2, 1935
Publication numberUS 2191121 A, US 2191121A, US-A-2191121, US2191121 A, US2191121A
InventorsLouis B Slichter
Original AssigneeSchlumberger Well Surv Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Geological surveying apparatus
US 2191121 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

Feb 20, 1940. 1 B SUCH-TER 2,191,121

GEOLOGICAL SURVEYING APPARATUS Original Filed March 2, 1935 2 Sheets-Sheet l g4 ATTORNEYS Feb. 20, 1940. 1 B, SUCHTER 2,191,121

GEOLOGICAL SURVEYING APPARATUS Original Filed March 2, 1935 2 Sheets-Sheet 2r INVENTOR Patented Feb.. 20, 1940 UNITED STATES PATENT OFFICE GEOLOGICAL SURVEYING APPARATUS Louis B. Slichter, Belmont, Mass., assigner to Schlumberger Well Surveying Corporation,

Houston, Tex., a. corporation of Delaware 3 Claims.

The present invention relates to the exploration of drill holes and, more particularly, to the determination of the properties and characteristics of the various strata traversed by a drill hole by the use of compressional wave energy.

More specifically, the invention relates to new and improved wave receiving means for obtaining indications of compressional wave energy in a bore hole in a simple and highly eiective manner.

In my copending application Serial No. 9,046, of which this application is a division, there is described a method of exploring bore holes in which compressional wave energy is generated in a bore hole and compressional waves transmitted through the surrounding formations are picked up by suitable wave receiving means. By studying the characteristics of the compressional waves picked up, valuable information about the formations surrounding the bore hole may be obtained.

An object of the present invention is to provide new and improved compressional wave receiving means for picking up waves in a bore hole, which may be secured to a cable in a simple and highly eiective manner.

Another object of the invention is to provide new and improved compressional wave receiving means of the above character which may 'be moved with a minimum of eiort through a bore hole containing a iluid.

A further object of the invention is to provide a compressional wave receiver which is adapted to make contact with the walls of a bore hole whereby an eilicient transfer of energy from the surrounding formations to the receiver may be achieved.

According to the invention the receiver comprises a streamlined casing made in several parts 40 which are somewhat oval in shape and which when assembled provide a. central opening through which the cable may pass. The respective parts are adapted to be secured together about the cable in any suitable manner to form a streamlined body thereon.

In another embodiment of the invention means is provided for acoustically coupling the wall o1' the drill hole with the receiver. This modification is adapted to be used particularly in bore holes which do not contain a good sound propagating medium.

The invention may be better understood from the following detailed description of several embodiments taken in connection with the accompanying drawings, in which:

(Cl. ISI-0.5)

Figure 1 illustrates schematically an investigation system. in a drill hole;

Figure 2 shows schematically a wiring diagram for connecting the various units in the system of Figure 1;

Figure 3 is a view in section of a receiving unit constructed according to the invention and attached to a cable in a drill hole;

Figure 4 ls a view in plan of the receiver shown in Figure 3; and

Figure 5 is a view in partial section of a receiver adapted to be used in dry holes.

In the system shown in Figure 1, a soundgenerator or oscillator I may be provided towards the lower part of the well, or in any other desired position. The generator I may be supplied by energy transmitted through the cable 2, which cable may also act as a support for the generator I. The generator I may be of any suitable type and preferably is of the so called oscillator type used generally for sub-aqueous signalling. The generator I may act as a weight for the cable, or additional weight may be provided as shown by the weight 3 attached thereto.

At various points along the cable 2, there are 25 provided receiving units 4, 5 and 6, there being three shown in Figure 1, but it is understood that one or more units may be used if desired, and that two units may suffice. These units are individually connected through conductors forming a part of the cable. A pair of conductors may be used for each unit or in fact a single conductor may be used with a ground or with common wire return.

Each receiving unit 4, 5 and 6 may be providedl with two separate receivers, if desired, as indicated by I and 8, and the receiving unit itself may be made streamline as shown in Figures 3 and 4, which will be described later.

In Figure 2 there is shown a diagrammatic representation of the system set forth in Figure l. In this case an oscillator I is supplied by energy through the conductors I0 and II which may be twisted and shielded to prevent induction or disturbances of the receiving conductors which 45 also may be twisted and shielded within the cable 2. The units I and 8 may be of the magnetophone type, as indicated in Figure 2, in which the diaphragm I2 has an armature I3 inducing current in the windings I4 and I5 placed over the core I6. Each unit, such as I'I, I8 and I9, is connected respectively by the conductors 20, 2l and 22 to its respective amplifier and indicator 23, 24 and 25, in which an indicating meter such as 26 may be provided. Any other suitable means u may be used such as a bridge with a phone or galvanometer.

If desired, each unit 23, 24 and 26 may be respectively connected to recorders 21, 26 and 29, so that a permanent record can be kept of the intensity of the signal received at each receiver, or preferably of the relative intensities of the signals received at each receiver. These intensities may be plotted as ordinates on a curve, the abscissae corresponding to the points at which the receivers are placed in the drill holes.

In Figure 3 there is shown in greater detail the structures of the units 4, and 6. Such units each comprise a streamline case made oi.' two parts 30 and 3i which are somewhat oval in shape, and have, when put together, a center opening or hole through which the cable 2 may pass. The two parts 30 and 3l which may be made of wood or other suitable material are held together in any suitable manner, as for instance by machine or wood bolts or nuts 32,' 32, 32, 32, which as indicated in Figure 3 may be recessed in one half of the frame and covered by a cement filling as indicated by 33, 33.

When the half units are applied to the cable, the cable is firmly clamped within the unit and the unit gives an appearance somewhat of the shape of a football, the two parts being rmly held together by the clamping bolts. Each half unit 30 and 3| may be provided with a suitable receiver, as for instance a receiver 34 of the magnetophone type in which there is provided a diaphragm 35 held fast by bolts 36 to a flange 31 of the casing 38 of the magnetophone. The casing 38 may be held in the unit 30 by means of the bolts 39, a recess being formed within the unit 30 so that the casing will iit snugly into it.

Within the casing 38 there may be provided the two coils 40, forming with the U-shaped core 4| a magnet system which will set up-or generate a current when the diaphragm 35 vibrates. The coils 40 may be polarized with direct current, or permanent magnets may be used.` 'Ihe diaphragm 35 may be made flush with the surface of the half 30, which unit itself is substantially streamlined about the conductor. The cable 2 may contain a supporting core to support the weight of the cable itself and the receivers that are down deeper in the drill hole, and similarly the cable 2 may be provided with groups of twisted leads for the various receiving units.

The half 30 and the half 3| may both be provided with sound receivers and while these may be individually connected with their indicators and recorders, nevertheless, it is preferable to operate both receivers in parallel or series and place them as indicated in Figure 1, on either side of the streamline unit. The receivers themselves may be held in the units by means of screw or machine bolts 42 and the leads to transmit the energy picked up by the vibrations of the diaphragm 35 may be connected to the cable 43 passing through the casing 38 and through the outer cable shield 44 of the cable itself.

A great part of the exploration is to be done in drill holes that are filled with water as indicated by 45 in Figure 1. In this case the Water serves as the chief propagating medium for the transmission of the compressional waves in the well. However, the analogous procedure may be utilized in a dry hole. In this case the source communicates its vibrations to the air, and the receivers receive energy from the air. Furthermore, instead of transmitting the energy through the air in the hole or through water in the hole,

the energy might be transmitted through the walls of the hole by impressing thevibrations upon the walls of the hole and receiving them from the walls of the hole.

For this purpose a contacting cap or convex plate 46, as indicated in Figure 5 may be provided, which element may be somewhat resilient and be supported against the diaphragm 35 by means of a spring support 41 or in any other suitable manner. 'Ihe spring 41 may be held in any Way to the resilient cap 46 and the diaphragm 35 such as by welding or by some mechanical attachment. 'Ihe cap 46 should be made of sufv ilcient height so that as the receiver is lowered down into the drill hole, the cap 46 will press against the side walls of the drill hole and make a good acoustic connection between the walls of the drill hole and the diaphragm 35. By providing caps to both diaphragms sound energy may be picked up quickly on both.

In the operation of the system it should be noted that while the sound waves may travel uniformly through the water in the drill holes, nevertheless, due to the character of the sides of the hole, the observation of the sound travelling down the sides of the hole, will vary, dependent to a great extent upon the character or porosity of the earth at the sides of the hole. The observation of the sound energy at a given distance down in the hole depends upon the character of the sound energy, particularly the frequency and ultimately upon the porosity of the material forming the walls of the hole.

The porosity of the wall rock of a drill hole is of importance practically in the determination of the flow of oil from the oil rock or sand or the ow of water into the hole and may be measured by the comparative or absolute intensities of the sound waves picked up by the various receiving units.

Since the absorption per unit length will be greater at the audible frequencies than in the range of sub-audible frequencies or seismic vibrations, it will readily be seen that the use of audible vibrations has a distinct advantage in the present invention. This is particularly true where there is good transmission in the drill hole, because the absorption is small and more diiiicult to measure.

Where the well is dry, the modification shown in Figure 5 may be used, in which case the cap 46 is placed against the side of the drill hole through the spring 41 and the sound energy is conveyed to the receiver by the contact of the plate 46, the spring 41 operating against the diaphragm 35. Other means may be provided for acoustically coupling the side of the drill holes with the receiver, but in each case it should be remembered that the units must not be held so tightly against the side walls of the drill hole that the cable cannot be lowered.

Observations may be taken with the cable part way or all the way down in the drill hole. It is preferable in making such observations to keep the distance of the receiving units at a constant spacing one from the other and from the source, and this is possible by clamping the units as indicated in Figure 1, directly to the cable itself.

It will be evident from the foregoing that the invention provides compressional. wave receiving means for use in bore holes which may be assembled in any desired position upon the cable with great ease. Furthermore, by reason of the streamlined shape of the receiver casing, the

receiving means may be moved through a bore hole containing a uid with a minimum of effort.

While several specific embodiments have been described above, the invention is not intended to be in any way limited thereby but is susceptible of numerous changes in form and detail Within the scope of the appended claims.

I claim: l

1. In a device of the type described, a cable, a streamline body composed in two parts, and adapted to fit over the cable, the cable passing centrally therethrough, means for clamping the streamline body together about the cable, and means providing a sound receiving device Within the stream-line body having a diaphragm contained within the surface of the streamline body.

2. In a device of the type described, adapted to be lowered into a drill hole, a cable. a streamline body attached to said cable, and having a receiver contained therein, and a spring contact element projecting from the streamline body and making an elastic connection between the receiver and the wall of the hole.

3. In a device of the type described adapted to be lowered into a drill hole, a cable, a body attached to said cable having a receiver contained therein and means projecting from said receiver body for making contact with the wall of the drill hole and providing vibrational coupling means between the receiver and the lwall of the drill hole.

LOUIS B. SLICHTER.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2483770 *Dec 22, 1945Oct 4, 1949Standard Oil Dev CoApparatus for seismic prospecting
US2496648 *Jun 24, 1943Feb 7, 1950Texaco Development CorpSeismic exploration system for determination of strata dips
US2503904 *Jun 30, 1944Apr 11, 1950Socony Vacuum Oil Company IncoSeismic prospecting method
US2539220 *Jun 22, 1944Jan 23, 1951Continental Oil CoSeismographic record correlation system
US2551417 *Jun 27, 1946May 1, 1951Standard Oil Dev CoApparatus for seismic exploration
US2568851 *Mar 7, 1942Sep 25, 1951 Detector carrier for seismic
US2578133 *Nov 8, 1944Dec 11, 1951Seismograph Service CorpSystem of seismic recording
US2580636 *Mar 1, 1945Jan 1, 1952Texas CoReflection seismic exploration
US2590530 *Mar 10, 1948Mar 25, 1952Socony Vacuum Oil Co IncSeismic prospecting system
US2590531 *Mar 10, 1948Mar 25, 1952Socony Vacuum Oil Co IncSelector arrangement for seismic prospecting system
US2596023 *Dec 16, 1944May 6, 1952Eastman Oil Well Survey CoAudio caliper device
US2757355 *Jul 3, 1953Jul 31, 1956United Geophysical CorpSeismic prospecting apparatus
US2825044 *Aug 2, 1949Feb 25, 1958Glen PetersonMethod of and apparatus for investigating subterranean strata
US2887172 *Nov 30, 1953May 19, 1959Robertshaw Fulton Controls CoWell logging methods and apparatus
US2902668 *May 28, 1956Sep 1, 1959Western Geophysical CoPressure sensitive device
US2915738 *Jan 22, 1957Dec 1, 1959Shell DevHydrophone detector
US2959241 *Dec 8, 1955Nov 8, 1960Schlumberger Well Surv CorpApparatus for investigating earth formations
US3263768 *Jul 2, 1962Aug 2, 1966Vector Cable CompanyDetachable mount for magneto-strictive detector
US3456754 *Sep 3, 1957Jul 22, 1969Socony Mobil Oil Co IncTransmission circuits for well logging systems
US3593255 *May 29, 1969Jul 13, 1971Marathon Oil CoAcoustic logging tool having opposed transducers
US3991850 *Jan 8, 1975Nov 16, 1976Schlumberger Technology CorporationNoise-attenuating positioners for acoustic well-logging tools
US4953136 *Jul 18, 1986Aug 28, 1990Schlumberger Technology CorporationDownhole seismic exploration device and apparatus
US5044460 *Mar 8, 1990Sep 3, 1991Schlumberger Technology CorporationDownhole seismic exploration device and apparatus
US5044461 *Jan 10, 1991Sep 3, 1991Western Atlas International, Inc.Decoupled borehole sensor
US9081110 *Dec 18, 2012Jul 14, 2015Schlumberger Technology CorporationDevices, systems and methods for low frequency seismic borehole investigations
EP0953158A1 *Dec 18, 1997Nov 3, 1999Input/Output, Inc.Hydrophone housing for a solid marine seismic cable
EP0961940A1 *Dec 18, 1997Dec 8, 1999Input/Output, Inc.Solid marine seismic cable assembly
Classifications
U.S. Classification181/102, 367/25, 181/401
International ClassificationG01V1/20
Cooperative ClassificationG01V1/201, Y10S181/401
European ClassificationG01V1/20B