MXPA96004923A - Method and apparatus for installing electronic equipment under a soft layer of the tie surface - Google Patents

Abstract

A method to monitor mineral deposits in production, including the method: permanently install a geophone in a drill hole, generate a first series of seismic waves, receive a first series of seismic data with the geophone, record the first series of data from the reception of a first series of seismic data, generate a second series of seismic waves after enough time has elapsed for the conditions in the reservoir to have changed, since the first series of seismic waves was generated, to receive a second series of seismic data with the geophone, and record the second series of seismic data from the reception of the second series of seismic data. A method for installing instruments below the surface of the earth, comprising the method, drilling a drill hole with a drilling device, inserting an instrument into the drill hole and permanently attaching the instrument to the drill hole. An instrument for receiving seismic data, the instrument comprising: a geophone component operating in an X direction, a geophone component operating in a Y direction, a geophone component operating in a Z direction, and a housing for the components of geophone, which is permanently fixed in a drilling hole

Description

METHOD AND APPARATUS FOR INSTAL ELECTRONIC EQUIPMENT UNDER ONE SOFT LAYER OF THE LAND SURFACE FIELD OF THE INVENTION This invention relates to methods and apparatus for gathering geological information, for the purpose of monitoring the production and exploration of minerals.

BACKGROUND OF THE INVENTION As the value of oil and gas continues to rise, there has been growing interest in methods to effectively recover all minerals from known mineral deposits, and to discover new deposits. Information about the depletion regime and the migration of minerals within a mineral deposit allows operators to apply the most effective production techniques for the particular conditions of the deposit. Accurate monitoring of mineral depletion, from a given reservoir, requires that exact investigations be multiplied over a long period of time. Also because the deposits in different sites and differently coupled give altered results, it is necessary to place seismic receivers and couple them in a similar way for the investigations carried out at different times. An example of a previous method involves dril a production well, inserting a three-dimensional geophone instrument for data collection and removing the instrument for the production of ore from the hole in the well. A three-way geophone is capable of detecting P waves and S waves. This allows the interpretation of: lithography, porosity, type of fluid in the pores, shape of the pores, depth of buried consolidation, anieotropic changes in pressure and anisotropic changes in temperature. However, if subsequent readings are to be obtained, production must be suspended and the instrument inserted back into the hole in the well. The position and coup of the geophone r-eceptor will not be the same as before and, therefore, will produce data deviated from those taken initially. Thus, even when this method detects S waves and also P waves, it is difficult to compare subsequent scans, due to the difference in the placement and coup of the geophone. A second example of a previous method involves depositing geophones at various points on the surface and taking readings. Once the exploration is complete, the receivers are retrieved for subsequent use in another exploration project. In an exploration in the ocean, the layer of water and mud typically kills the S waves, so that they do not propagate upwards in the mud or water, where they could be received by the seismic instruments placed there. This also applies to the surface of the soft or soft earth in terrestrial explorations. Thus, the data collected on the surface is not as accurate as the data collected from the depth, inside a drill hole. In addition, as in the previous method, if exploration data are to be collected at a later time, the receivers must be deposited again on the surface. Again, it is not likely that the receivers are placed and coupled as in the first scan. Therefore, in order to provide accurate reservoir scans, over time, there is a need for the possibility of repetition in the location of the seismic receivers and in the detection of both the S wave and the P wave signal.

BRIEF DESCRIPTION OF THE INVENTION According to one aspect of the invention, a method is provided for monitoring mineral deposits in production. One modality of this aspect comprises: instal -permanently- a geophone in a dril hole; generate a first seine of seismic waves; receive a first series of seismic data with the geophone; register the first series of data of said reception of the first series of seismic data; generate a second series of seismic waves, after enough time has elapsed for the conditions in the reservoir to have changed since the first series of seismic waves was generated; receive a second series of seismic data with the geophone; and record the second seismic data of the reception of the second series of seismic data. In accordance with another aspect of the invention, a method for installing instruments below the surface of the earth will be provided. One modality of this aspect comprises: drilling a drilling hole with a drilling apparatus; insert an instrument in the well hole; and permanently fix the instrument in the hole of the well. In accordance with yet another aspect of the invention, an instrument for receiving seismic data is provided. One embodiment of the aspect comprises: a geophone component operating in an X direction; a geophone component that works in a Y direction; a geophone component that works in a Z direction; and a housing for the geophone components that is permanently fixed in the hole of the well. In accordance with a further aspect of the invention, a system for collecting seismic information is provided. One embodiment of this aspect comprises: a signal source; a signal receiver, permanently fixed in the hole; a control unit that sends and receives information to and from the signal source and the signal receiver; and data communicators between the control unit and the signal receiver and the signal source. According to a further aspect of the present invention, a method is provided for monitoring mineral deposits in production. One embodiment comprises: installing a tube permanently in a drilling hole; download in a first case, an electronic instrument inside the tube; read a first series of data with the electronic instrument; remove the electronic instrument from the tube; lower, in a second case, the electronic instrument inside the tube, after a sufficient time has elapsed so that the conditions in the deposit have changed; and read with the electronic instrument a second series of data.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is better understood when reading the following description of non-limiting modalities, with reference to the accompanying drawings, in which the same parts in each of the different figures are identified with the same reference sign; and which are briefly described as follows: Figure 1 is a sectional view of an instrument in a vertical well hole; Figure 2 is a schematic of a method for installing an instrument in a vertical well hole; Figure 3 is a sectional view of a perforating apparatus with coil tube; Figure 4a is a sectional view of a seismic instrument to be used in a vertical well hole; Figure 4b is a sectional view of a seismic instrument to be used in a vertical well hole; Figure 4c is a sectional view of a seismic instrument to be used in a vertical well hole; Figure 4d is a sectional view of a seismic instrument to be used in a vertical well hole; Figure 4e is a sectional view, taken in the direction of the Z axis of the instrument, in the geophone X; Figure f is a sectional view, taken in the direction of the Z axis, of the instrument in the geophone Y; Figure 4g is a sectional view, taken in the direction of e e Z, of the instrument in geophone Z; Figure 5 is a diagram of a configuration of the instrument connected to a tube to be inserted in the hole of the well; Figure 6 is a diagram of a configuration of the instrument connected to a tube to be inserted in the hole of the well; Figure 7 is a schematic of a method for monitoring a reservoir in production; Figure 8 is a diagram of a configuration of the invention, with an instrument connected to the outside of a tube, and with an instrument connected to the interior of the tube; and Figure 9 is a diagram of a configuration of the invention, with an upper section of the tube removed. However, it should be noted that the appended drawings illustrate only the typical embodiments of the invention and, therefore, should not be considered to be a limit to the scope of the invention, which includes other equally effective modalities.

DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, a cross-sectional view of a vertical well (1) for a seismic instrument and a scheme of a method for installing the instrument is shown. The method comprises piercing (201) a first section (2) of the well at a depth of approximately 15 m. This first section (2) is relatively wider than the second, deeper section (3) of the well, which is not yet drilled. A casing pipe (10) of greater diameter, (for example, from 8.89 to 11.42 cm), is installed (202) in the first section (2). The space between the casing pipe (10) and the earth is filled (203) with cement to permanently fix the casing pipe (10) in position. A section (3) of smaller diameter (for example, of about 6.09 cm) is then perforated (204) below the casing (10) of greater diameter, at a depth of about 210 to 304 m (this depth it could be much greater, given the particular environment that surrounds the well hole). Then a seismic instrument (40) is connected to the tube (30) and the tube (206) is inserted into the well (1). The end of the tube (30) extends case to the bottom of the well (1) and the instrument (40) is connected to the tube (30) at a depth of approximately 90 to 120 meters (this depth can be changed, according to the desired instrument configuration). Cement (207) is then pumped into the tube (30) so that it flows along the tube (30) and out through a hole (31) in the bottom. Concrete first fills the space that exists between it. tube (30) and section (3) of smaller diameter) and encloses the instruments (40). Finally, the concrete fills the space between the tube (30) and the casing (10) of greater diameter. Once the concrete sets, the instrument (40) is permanently fixed in the well (1). The instruments can be installed in this way both on the ground and inside. In some environments, the instruments can be fixed in the hole of the well, allowing the walls of the hole in the well to fall on the instrument. Sometimes this provides a superior coupling of the instrument to the surrounding formation, due to the uniformity of the material around the instrument. As the cost of drilling equipment becomes less expensive, it will be more efficient to directly connect the seismic instrument to the coil tube itself. Then the coil tube is left in the well hole while the instruments are permanently fixed in the hole of the well. Concrete is pumped into the hole in the well, through the coil tube, so that it flows up and around the instruments, as before. The drill bit or drill bit and the motor to go down into the well are permanently fixed in the hole of the well, as well as the instruments. This method is preferred when it is less expensive to leave the drilling apparatus in the hole of the well than to remove it from it. A high-pressure water nozzle is a type of drilling device that, eventually, is so bar-ato that it deserves to be left in the hole of the well. Referring to Figure 3, there is shown a bobbin tube drilling apparatus (310). The drill bit or drill bit (301) is driven by a motor (302) that operates inside the well. The motor (302) that operates inside the well is powered by the pressure of the mud pump, which is pumped by a pump (304) on the surface. A coil tube (305) connects the pump (304) to the motor (302) that operates inside the well. As the drill hole (306) is drilled deeper, the coil tube (305) is unwound from a tube reel (307) and onto a wheel (308). The wheel (308) is positioned over the hole (306) of the well, so that the coil tube (305) can extend from the wheel (308) downwardly into the hole (306) of the well. An example of a perforating device (310) with a coil tube is the Fleet model 40-20 coiled tubing unit, produced by Vita International, Inc. This unit has the following characteristics: Injection Head Regime: up to 18,160 kg. Transmission: Planetary transmission to Catarina and final chain, hydrostaticarnente powered. Speed: 67.05 n max. Braking system: Main brake: wet type, with fail safe; auxiliary brake: band type, powered by air.

Straightener: Manual / hydraulic system. Grip system: Leb? S slot with multiple maintenance rollers. Size scale: Up to 8.89 cm. Mounted on skids, truck, trailer. Leveling and hydraulic centering. Mast: Up to 9 m for wellhead clearances with self-loading capacity / storage reel / rabbet discharge.

Optional equipment: winches, pumps, etc., according to customer needs. Motor-generator equipment: Diesel up to 200 HP. Hydraulic system: Injector and storage / work reels: Sunstrand Hydrostatic, maximum pressure: 351.5 kg / c2. Leveling, elevation, winds and lateral placement: Conventional gear type pump with maximum pressure of 210.9 kg / cm2. Storage / work reel flange diameter: 3.04 rn. Outside diameter - diameter of core pipe Capacity 6.03 cm 2.43 m 914.4 rn 5.08 c 2.03 m 2,133.6 m 4.44 cm 1.82 2.926.08 m 3.81 cm 1.82 m 4.267.2 rn 3.17 cm 1.82 5.791.2 rn 2.54 crn 1.82 rn 9.144.0 rn Tube reel holder: The side frames are hydraulically opened to facilitate the change of the reels. Controls: A. Electric on the hydraulic for the reel-injector, storage and displacement reel (rolled up). B. Conventional to raise, level, center, winches, etc. Available installed in the control cabin, mounted on the truck or trailer. Row A is available with remote capacity up to 15 rn. Referring to Figure 4a, there is shown a seismic instrument (401) for permanent fixation in a drill hole, as seen along the Y axis. The instrument (401) comprises three geophones: A geophone X (402 ) placed to read the waves along an X axis; a geophone Y (403) positioned to read the waves along an ee Y and a geophone Z (404) arranged to read the waves along a Z axis. A cable (405) runs through the instrument (401) ) to transmit the readings received by the geophones. The instrument (401) also has a sealed housing structure (406) that seals the cable (405) and the geophones (402), (403) and (404) within it. The cable itself (405) is sealed in portions extending outside the housing (406). The cable portions (405) disposed inside the housing (406) are at connection points that connect to the geophones. Thus, in order to maintain a watertight barrier for the entire instrument (401), seals (407) are formed between the cable (405) and the housing (406), where the cable (405) enters the housing (406) in both extremes. The internal seals (408) also form a tight barrier between the housing (40b) and the cable (405). The cable (405) and the housing (406) can be sealed with glass, epoxy or toroidal rings, depending on the particular application. They are also p > We can see other types of instruments. These include: a temperature instrument, a pressure instrument, a hydrophone, a gravimetric resistance instrument, a resistivity instrument, an electromagnetic instrument and a radiation sensing instrument. Referring to Figure 4b, the housing (405) and the geophones (402), (403) and (404) as seen following an X axis are illustrated therein. Referring to Figure 4c, the housing is shown. (405) and the geophones (402), (403) and (404) as seen following a Y axis. Referring to Figure 4d the housing (405) and the geophones (402), (403) and ( 404) as seen along a Y axis. In Figure 4f, the geophone Y (403) is shown as seen following the Z axis. Figure 4g shows the geophone Z (404) as seen following the Z axis. Note also in Figures 4e-4g that there are holes (411), (412) and (413) in the housing (406). The cable (405) passes through these holes and connects with each geophone. Referring to FIG. 5, a configuration for connecting the instrument to the tube is shown. In that configuration, a centering means (501) that is fixed to the tube (502) is used., to insert the instrument (503). The centering device comprises upper and lower collars (504) and upper and lower arches (505) that extend between the collars (504) and connect them. The arcs (505) are somewhat flexible and have an outer diameter greater than the collars (504), so that they can be flexed against the sides of the drilling hole to prevent the pipe from contacting the sides of the drilling hole. . A cable (506) extends from both ends of the instrument (503) and is connected to the tube (502) by the upper and lower collars (504). Additionally the instrument (503) can be attached to the tube (502) by winding sealing tape around the instrument (503) and the tube (502). With reference to Figure 6 a configuration for connecting the instrument to the tube is shown. In that configuration two centering means (601) and (604) connect the cable (606) to the tube (602). Here, no centering device encloses the instrument, but rather a centering device - it is located on top (601) of the instrument and another below (604) of it. Again the instrument (603) can be attached to the tube (602) by winding tape around both the instrument (603) and the tube (602). It should also be understood that it is pble to join multiple instruments to a single tube in several locations. Multiple centering devices can also be attached in various locations to prevent contact of the tube with the sides of the drilling hole. A centering device could be connected every 3 meters, even where there are no instruments connected. Referring to Figure 7, a method for monitoring the ore deposit in production is shown. The method consists in permanently installing a seismic instrument in the substrates near the deposit to be monitored. This is done by drilling (701) a drilling hole with a drilling apparatus. Then a seismic instrument, such as a three-dimensional geophone, is inserted (702) into the hole. The instrument is then permanently fixed (703) in the well hole by filling the well hole with concrete. This not only fixes the position of the instrument in one place, but also couples the instrument to the substrates. The coupling allows the instrument to perceive seismic waves that travel through the strata because the instrument is actually connected to the strata. The next step in the method is to generate (704) a first series of seismic waves. These waves are reflected in the strata and are received (705) by the instrument. These data are recorded (706) so that the mineral producers are aware of the conditions of the deposit at that point of time. Subsequently a second series of seismic waves (707) is generated. These waves are again reflected in the strata and are received (708) by the instrument. This second series of data is also recorded (709) to compare it with the first series of data. In this method you can also place the seismic source in a drill hole, adjacent to the drill hole for the receiving instruments. This allows the seismic wave to travel from the seismic source to the lower strata; is reflected back to the surface, and is received by the receiving instruments, without moving through a surface layer of soft earth, killing of S wave.

Referring to figure 8, a configuration of the instruments placed inside the hole is shown. In that embodiment an instrument (40) is connected to the outside of the tube (30). The tube (30) is inserted into the hole, so that the instrument (40) is approximately half the depth of the hole in the well. The tube (30) is permanently fixed in the hole of the well by pumping concrete towards the center of the tube (30), so that the concrete comes out through the hole (31) disposed at the bottom of the tube (30). Then the concrete rises in the hole (3) between the tube (30) and the walls of the well hole, so that it surrounds the instrument (40). A plunger (60) is then used to push the concrete downward, along the tube, so that the inside of the tube, above the plunger (60), m is not filled with concrete. A second instrument (50) is placed below, inside the tube, to obtain readings. This instrument (50) can be recovered and reinserted each time it is desired to obtain readings. A similar embodiment of the invention consists in installing the tube without attaching an instrument (40) to the exterior- of the tube (30). The cement inside the tube (30) is again removed by the plunger (60). In this mode there are no permanently fixed instruments in the hole of the well. Rather, the instruments inside the tube are lowered to read the readings. Once the readings are taken, the instruments are taken out for use in other locations. Each time it is necessary to take readings, the instruments are simply lowered inside the tube. Referring to Figure 9, a diagram of a configuration for installing the instruments under a soft or soft layer of the earth's surface is shown. In this configuration the instrument (40) is attached to the outside of the tube (30) and the space between the tube (30) and the walls of the drilling hole is filled with concrete, as well as the inside of the tube (30). The detachment of the upper portion of the tube (30) is a particular feature of this method. The tube (30) and the drill hole (3) are covered with earth. This prevents the upper part of the tube (30) from acting as an antenna, isolating the instruments from the vibrations generated at and above the surface of the earth. These vibrations tend to interfere with the seismic readout that is obtained by the instruments. It should be noted that the embodiments described above illustrate only typical embodiments of the invention and, therefore, should not be considered to be a limit to the scope of the invention, which includes other equally effective modalities.

Claims (52)

NOVELTY OF THE INVENTION CLAIMS

1. - A method for monitoring a mineral deposit in production, characterized in that the method comprises: permanently installing a seismic instrument in a drilling hole; generate a first series of seismic waves; receive a first series of seismic data, with the seismic instrument; record the first data series of the reception of the first seismic data series; generate a second series of seismic waves after a sufficient time has elapsed for the conditions in the reservoir to have changed with respect to those of the generation of a first series of seismic waves; receive with the seismic instrument a second seismic data item; record the second series of seismic data from the reception of the second series of seismic data.

2. A method according to claim 1, further characterized in that the permanent installation comprises: drilling a drilling hole with a drilling apparatus; inserting an instrument into the drill hole; and permanently fix the seismic instrument in the drill hole.

3. A method according to claim 1, further characterized in that the permanent installation comprises installing a plurality of seismic instruments.

4. A method according to claim 1, further characterized in that the seismic instrument of the group consisting of a geophone, a hydrophone, a pressure instrument and an electromagnetic instrument is selected.

5. A method for installing instruments below the surface of the earth, characterized in that said method comprises: drilling with a drilling apparatus a drilling hole; inserting an instrument into the drill hole; and permanently fix the instrument in the drill hole.

6. A method according to claim 5, further characterized in that the drilling comprises drilling with a tube drilling apparatus wound.

7. A method according to claim 5, further characterized in that drilling comprises drilling with a nozzle at high pressure.

8. A method according to claim 5, further characterized in that the drilling comprises energizing a motor close to a drilling bit or drill bit, wherein the motor drives the drilling bit or drill bit.

9. A method according to claim 5, further characterized in that p > erforating involves rotating a string of tubing connected to a drill bit or drill bit that drives the drill bit or drill bit.

10. A method according to claim 5, further characterized in that drilling comprises: drilling a hole of shallow depth and large diameter; insert a large diameter casing pipe into the shallow, large diameter hole; fill with cement a space between the outside of the large diameter casing and the inside of the large diameter hole; drill a deep hole, small diameter, from inside and below the shallow hole and large diameter.

11. A method according to claim 5, further characterized in that inserting comprises joining the instrument to a tube and lowering the tube into the drill hole.

12. A method according to claim 5, further characterized in that inserting comprises joining the instrument to a tube of the drilling apparatus.

13. A method according to claim 5, further characterized in that the instrument to be inserted is selected from the group consisting of a geophone, a temperature instrument, a pressure instrument, a hydrophone, a gravity resistance instrument. ETRIC, an instrument of resistivity, an electromagnetic instrument and an instrument sensitive to radiation.

14. A method according to claim 5, further characterized in that fixing comprises filling the drill hole with cement.

15.- A method in accordance with the claim 14, further characterized in that filling comprises pumping cement downwards, inside the tube, so that the cement comes out at the bottom of the tube and fills the space between the tube and the drilling hole, from the bottom of the tube to the upper end of the tube.

16.- A method according to the claim 15, further characterized in that the filling further comprises pushing the cement down the inside of the tube, with a plunger, so that a portion of the interior of the tube, above the plunger, is accessible from the upper end of the tube.

17. A method according to claim 5, further characterized in that the fixation comprises collapsing the drill hole so that it collapses on the instrument.

18. A method according to claim 1 5, further characterized in that it further comprises retracting the piercing apparatus.

19. A method according to claim 18, further characterized in that the retraction comprises crushing a drill bit or drill bit and pulling it upwards, through the inside of a tube.

20. An instrument for receiving seismic data, characterized in that the instrument comprises: a geophone component operating in an X direction; a geophone component that works in a Y direction; a geophone component that works in a Z direction; and a housing for the geophone components, which is permanently fixed in a drill hole.

21. An instrument according to claim 20, further characterized in that the housing is sealed.

22. An instrument according to claim 21, further characterized in that the housing is sealed with epoxy.

23. An instrument according to claim 21, further characterized in that the housing is sealed with glass.

24. An insument in accordance with claim 20, further characterized in that the housing is attached to a tube.

25. - An instrument according to claim 24, further characterized in that the housing is attached to the outside of a tube.

26. An instrument according to claim 24, further characterized in that the housing is attached to the interior of a tube.

27. An instrument according to claim 24, further characterized in that the tube does not extend upwards to a soft layer of the surface of the earth.

28.- A system for collecting seismic information, characterized in that the system comprises: a signal source; a signal receiver, permanently fixed in a drilling hole; a control unit that sends and receives information to and from the signal source and from the signal receiver; and co unicators of data between the control unit and the. r-eceptor signal and signal source.

29.- A system in accordance with the claim 28, further characterized in that the signal receiver comprises: a geophone component operating in an X direction; a geophone component that works in a Y direction; a geophone component that works in a Z direction; and an accommodation for the geophone components.

30. - A system according to claim 28, further characterized in that the housing is sealed.

31. A system according to claim 30, further characterized in that the housing is sealed with epoxy.

32. A system according to claim 30, further characterized in that the housing is sealed with glass.

33. A system according to claim 28, further characterized in that the communicator is a cable that extends from the housing to the surface of the earth.

34. A system according to claim 28, further characterized in that the co-processor is a transmitter of information to the surface of the earth.

35.- A system according to claim 28, further characterized in that the corn? Nidor is sealed.

36.- A system for installing an instrument below the surface of the earth, characterized also because the method is compressed:? N driller- to drill? N drilling hole; an inserter of an instrument inside the drill hole; a fixative of the instrument to fix it permanently in the hole of the well.

37.- A system according to claim 36, further characterized in that the perforator comprises a rolled tube perforator.

38.- A system in accordance with the claim 37, further characterized in that the perforator comprises a drilling module near a drill or drill bit, extending from a lower end of a tube, wherein the drilling module drives the drill bit or drill bit.

39.- A system according to claim 36, further characterized in that the perforator comprises a rotating pipe string connected to a drill or drill bit, which rotates the drill bit or drill bit.

40.- A system in accordance with the claim 35, further characterized in that the perforator comprises a nozzle.

41. - A system in accordance with the claim 36, further characterized in that the inserter comprises a tube to which the instrument is attached.

42.- A system according to claim 36, further characterized in that the inserter- comprises a tube of the rolled tube perforator.

43. A system in accordance with the claim 36, further characterized in that the fixator comprises a tube for filling the drill hole with cement.

44.- A system in accordance with the claim 36, further characterized in that the inserter and the fixator comprise a tube to which the instrument is attached, and through which cement p > To fill the drilling hole with cement.

45.- A system according to claim 36, further characterized in that the perforator, the inserter and the fastener comprise a tube having a drill bit or drill bit in a p > lower orcion, and to which the instrument is attached; and through which cement is pumped to fill the drill hole with cement.

46.- A system in accordance with the claim 36, further characterized in that the instrument comprises: a geophone component in an X direction; a geophone component in a Y direction; and a geophone component in a Z direction.

47.- A system in accordance with the claim 46, further characterized in that the instrument further comprises a housing structure for the geophone components.

48. A system according to claim 46, further characterized in that the instrument additionally provides connectors that communicate the information received by the geofono components.

49.- A method for monitoring mineral deposits in production, characterized in that the method comprises: drilling * a drilling hole, which is not for production, under the soft layer of the earth's surface, with a rolled pipe driller; insert a tube inside the punching hole; fill with cement the space between the outside of the tube and the inside of the drill hole; download in the first case an electronic instrument inside the tube; read a first series of data with the electonic instrument; remove the electronic instrument from the tube; lower, in a second case, the electronic instrument inside the tube, after enough time has passed for the conditions in the reservoir to have changed since it was first lowered; and read a second series of data with the electronic instrument.

50.- A method of compliance with the claim 49, further characterized in that the filling comprises pumping-cement down the inside of the tube, so that the cement exits at the lower end of the tube and fills the space between the tube and the bore hole, from the bottom of the tube towards the top of the tube.

51.- A method of compliance with the claim 50, further characterized in that the filling further comprises pushing the cement down the inside of the tube with a plunger, so that a portion of the inside-of the tube, above the plunger, is accessible from the upper end of the tube.

52. A method according to claim 49, further characterized in that the instrument to be inserted is selected from the group consisting of a geophone, a temperature instrument, a pressure instrument, a hydrophone, a gravimetric resistance instrument , an instrument of resistivity, an electromagnetic instrument and a radiation sensor instrument.