DOWNHOLE MARKERS
The present disclosure relates to one or more methods and apparatus to dispose one or more markers within a subterranean formation. The method includes positioning a drill probe assembly in a borehole extending into the subterranean formation, drilling a hole through a sidewall of the borehole with a flexible shaft of the drill probe assembly, the hole penetrating the subterranean formation, and disposing a marker in the hole.
Wells are generally drilled into the ground or ocean bed to recover natural deposits of oil and gas, as well as other desirable materials that are trapped in geological formations in the Earth's crust. Wells are typically drilled using a drill bit attached to the lower end of a drill string. Drilling fluid, or mud, is typically pumped down through the drill string to the drill bit. The drilling fluid lubricates and cools the bit, and may additionally carry drill cuttings from the borehole back to the surface.
In various oil and gas exploration operations, it may be beneficial to have information about the subterranean formations that are penetrated by a borehole. For example, certain formation evaluation schemes include measurement and analysis of the formation pressure and permeability. These measurements may be essential to predicting the production capacity and production lifetime of the subterranean formation.
Furthermore, additional formation evaluation schemes include placing radioactive markers in the subterranean formation along the borehole at predetermined intervals to measure formation changes over time. Typically, a first tool is run down the borehole, and radioactive markers, formed as bullets, are fired into the formation using explosives. After the placement of radioactive markers in the subterranean formation, a second tool featuring an array of gamma ray detectors is run down the borehole to measure the distance between the radioactive markers.
As such, subsequent measurements may show changes in the distance between radioactive markers, indicating compaction of the subterranean formation. Compaction of the subterranean formation may cause subsidence, defined as the local sinking of the Earth's surface due to changes occurring below the surface. However, traditional placement methods and techniques may be limited in operation, such as by requiring the use of explosives, and further requiring the placement of radioactive markers prior to casing the borehole to avoid residual holes. The methods may further be limited in that the penetration depth of the radioactive marker may not be controllable, thus, introducing uncertainty that may have a detrimental effect on the measurement quality.
The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.
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An upper end of the drill string 112 may be connected to the kelly 122, such as by threadingly connecting the drill string 112 to the kelly 122, and the rotary table 120 may rotate the kelly 122, thereby rotating the drill string 112 connected thereto. As such, the drill string 112 may be able to rotate with respect to the hook 124. Those having ordinary skill in the art, however, will appreciate that though a rotary drilling system is shown in
The wellsite 100 may include drilling fluid 128 (also known as drilling “mud”) stored in a pit 130. The pit 130 may be formed adjacent to the wellsite 100, as shown, in which a pump 132 may be used to pump the drilling fluid 128 into the wellbore 114. The pump 132 may pump and deliver the drilling fluid 128 into and through a port of the rotary swivel 126, thereby enabling the drilling fluid 128 to flow into and downwardly through the drill string 112, the flow of the drilling fluid 128 indicated generally by direction arrow 134. This drilling fluid 128 may then exit the drill string 112 through one or more ports disposed within and/or fluidly connected to the drill string 112. For example, the drilling fluid 128 may exit the drill string 112 through one or more ports formed within the drill bit 116.
As such, the drilling fluid 128 may flow back upwardly through the borehole 114, such as through an annulus 136 formed between the exterior of the drill string 112 and the interior of the borehole 114, the flow of the drilling fluid 128 indicated generally by direction arrow 138. With the drilling fluid 128 following the flow pattern of direction arrows 134 and 138, the drilling fluid 128 may be able to lubricate the drill string 112 and the drill bit 116, and/or may be able to carry formation cuttings formed by the drill bit 116 (or formed by any other drilling components disposed within the borehole 114) back to the surface of the wellsite 100. As such, this drilling fluid 128 may be filtered and cleaned and/or returned back to the pit 130 for recirculation within the borehole 114.
Though not shown, the drill string 112 may include one or more stabilizing collars. A stabilizing collar may be disposed within and/or connected to the drill string 112, in which the stabilizing collar may be used to engage and apply a force against the wall of the borehole 114. This may enable the stabilizing collar to prevent the drill string 112 from deviating from the desired direction for the borehole 114. For example, during drilling, the drill string 112 may “wobble” within the borehole 114, thereby enabling the drill string 112 to deviate from the desired direction of the borehole 114. This wobble may also be detrimental to the drill string 112, components disposed therein, and the drill bit 116 connected thereto. However, a stabilizing collar may be used to minimize, if not overcome altogether, the wobble action of the drill string 112, thereby possibly increasing the efficiency of the drilling performed at the wellsite 100 and/or increasing the overall life of the components at the wellsite 100.
As discussed above, the drill string 112 may include a bottom hole assembly 118, such as by having the bottom hole assembly 118 disposed adjacent to the drill bit 116 within the drill string 112. The bottom hole assembly 118 may include one or more components included therein, such as components to measure, process, and store information. The bottom hole assembly 118 may also include components to communicate and relay information to the surface of the wellsite.
As such, in
The LWD tool 140 shown in
The MWD tool 142 may also include a housing (e.g., drill collar), and may include one or more of a number of measuring tools known in the art, such as tools used to measure characteristics of the drill string 112 and/or the drill bit 116. The MWD tool 142 may also include an apparatus for generating and distributing power within the bottom hole assembly 118. For example, a mud turbine generator powered by flowing drilling fluid therethrough may be disposed within the MWD tool 142. Alternatively, other power generating sources and/or power storing sources (e.g., a battery) may be disposed within the MWD tool 142 to provide power within the bottom hole assembly 118. As such, the MWD tool 142 may include one or more of the following measuring tools: a weight-on-bit measuring device, a torque measuring device, a vibration measuring device, a shock measuring device, a stick slip measuring device, a direction measuring device, an inclination measuring device, and/or any other device known in the art used within an MWD tool.
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The tool 200 may have an elongated body 210 that includes a formation tester 212 disposed therein. The formation tester 212 may include an extendable probe 214 and an extendable anchoring member 216, in which the probe 214 and anchoring member 216 may be disposed on opposite sides of the body 210. One or more other components 218, such as a measuring device, may also be included within the tool 200.
The probe 214 may be included within the tool 200 such that the probe 214 may be able to extend from the body 210 and then selectively seal off and/or isolate selected portions of the wall of the borehole 204. This may enable the probe 214 to establish pressure and/or fluid communication with the subterranean formation F to draw fluid samples from the formation F. The tool 200 may also include a fluid analysis tester 220 that is in fluid communication with the probe 214, thereby enabling the fluid analysis tester 220 to measure one or more properties of the fluid. The fluid from the probe 214 may also be sent to one or more sample chambers or bottles 222, which may receive and retain fluids obtained from the formation F for subsequent testing after being received at the surface. The fluid from the probe 214 may also be sent back out into the borehole 204 or formation F.
Referring now to
Wired drill pipe may be structurally similar to that of typical drill pipe. However, the wired drill pipe may additionally include a cable installed therein to enable communication through the wired drill pipe. The cable installed within the wired drill pipe may be any type of cable capable of transmitting data and/or signals therethrough, such an electrically conductive wire, a coaxial cable, an optical fiber cable, and or any other cable known in the art. The wired drill pipe may include having a form of signal coupling, such as having inductive coupling, to communicate data and/or signals between adjacent pipe segments assembled together.
As such, the wired pipe string 312 may include one or more tools 322 and/or instruments disposed within the pipe string 312. For example, as shown in
The tools 322 may be connected to the wired pipe string 312 during drilling the borehole 314, or, if desired, the tools 322 may be installed after drilling the borehole 314. If installed after drilling the borehole 314, the wired pipe string 312 may be brought to the surface to install the tools 322, or, alternatively, the tools 322 may be connected or positioned within the wired pipe string 312 using other methods, such as by pumping or otherwise moving the tools 322 down the wired pipe string 312 while still within the borehole 314. The tools 322 may then be positioned within the borehole 314, as desired, through the selective movement of the wired pipe string 312, in which the tools 322 may gather measurements and data. These measurements and data from the tools 322 may then be transmitted to the surface of the borehole 314 using the cable within the wired drill pipe 312.
A flexible shaft assembly, and one or more methods of using a drill probe assembly, in accordance with the present disclosure may be included within one or more of the tools and devices shown in
Referring now to
The drill probe assembly 402 may include a plugging piston 408 that extends in substantially the same direction as the flexible shaft 406. The plugging piston 408 may be configured to push a marker 410, or multiple markers, at least partially, into a hole drilled by the flexible shaft 406. One or more markers 410 may be disposed in a holder 412, which may be, for example, a revolver, a magazine, and/or any other holder known in the art. The holder 412 may axially align the marker 410 with the plugging piston 408. As shown, the flexible shaft 406, the plugging piston 408, and/or the holder 412 may be attached to a moveable carriage 414 that is configured to move with respect to the borehole 404 and/or other components of the drill probe assembly 402 to align the plugging piston 408 and marker 410 with the hole drilled by the flexible shaft 406. The moveable carriage 414 may additionally align the flexible shaft 406, the plugging piston 408, and/or the holder 412 with the aperture 416 in the drill probe assembly 402 and/or a tool body (not shown) housing the drill probe assembly 402. Components of the drill probe assembly 402 may then be able to move with respect to the moveable carriage 414, such as by having the flexible shaft 406, the plugging piston 408, and/or the holder 412 to be able to move with respect to the moveable carriage 414. For example, the flexible shaft 406 and the plugging piston 408 may be able to extend from the moveable carriage 414.
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The present disclosure may be used to place multiple markers in the subterranean formation along the length of a borehole. Measurements may be taken between a marker and a second location, in which the second location may include a second marker and/or may include any other known location (e.g., a surface location). An initial measurement of the distance between the marker and a second location may be taken after placing the marker in the subterranean formation. Later measurements of the distance between the marker and the second location may then be taken and compared to the initial measurement. The changes in distance and comparison of the measured distances may indicate geological changes in the subterranean formation, such as, for example, compaction, expansion, sliding, shifting, and/or any other movement within the subterranean formation. Indications of compaction in the subterranean formation may provide information about possible subsidence at the surface.
One or more methods of measuring the distance between the marker and a second location may be used. For example, one such method may include running a measurement tool down the borehole, in which the measurement tool has at least one detector, such as a gamma radiation detector. These detectors may detect the markers disposed in the subterranean formation and measurements may be taken between the markers. One of ordinary skill in the art will appreciate that other types of markers, measurement tools, and/or methods of measuring may be used without departing from the scope of the present disclosure.
Advantageously, the present disclosure may provide a method to place a marker in a borehole formed within a subterranean formation such that the depth of the marker is controlled. Controlling the depth of the marker in the hole may provide more accurate measurements. Another advantage of the present disclosure may be the ability to place markers in the subterranean formation via a borehole with or without casing and/or cement. Additionally, the present disclosure may allow for the sealing of the casing after the placing the marker in the subterranean formation. The present disclosure may also use equipment from the present assignee, such as the CHDT™ (Cased Hole Dynamics Tester), available from Schlumberger®. Another advantage of the present disclosure may be the lack of requiring explosives to place markers within a subterranean formation, as explosives are restricted and/or regulated in many locations around the world.
In view of all of the above and the figures, those skilled in the art should readily recognize that the present disclosure introduces a method comprising: positioning a drill probe assembly in a borehole extending into a subterranean formation; drilling a hole through a sidewall of the borehole with a flexible shaft of the drill probe assembly, the hole penetrating the subterranean formation; and disposing a marker in the hole. The drill probe assembly may comprise a plugging piston, wherein the plugging piston is used to dispose the marker, at least partially, in the hole. The method may further comprise pushing the marker in the hole with the flexible shaft. The method may further comprise: drilling a through hole into a casing disposed within the borehole with the flexible shaft; and disposing a casing plug in the through hole formed in the casing. The hole may be a first hole and the marker may be a first marker, wherein the method may further comprise: re-positioning the drill probe assembly in the borehole; drilling a second hole through a sidewall of the borehole with the flexible shaft, the second hole penetrating the subterranean formation; and inserting a second marker into the second hole. The drill probe assembly may comprise a moveable carriage, a plugging piston, and the flexible shaft, wherein the flexible shaft is configured to move with respect to the moveable carriage. The drill probe assembly may further comprise a casing plug and a holder, the holder configured to have the marker and the casing plug disposed therein. The casing may be disposed within the borehole and cement may be disposed, at least partially, within an annulus formed between the casing and the borehole. The marker may comprise a radioactive material. The method may further comprise comprising measuring a distance between the marker and a reference location. The measuring the distance between the marker and the reference location may comprise disposing a measurement tool within the borehole. The marker may comprise a radioactive material and the measurement tool comprises a gamma radiation detector. The hole may be a first hole, the marker may be a first marker, wherein the reference location may comprise a second marker disposed in a second hole, the second hole penetrating the subterranean formation. The distance may be a first distance, and the method may further comprise: measuring a second distance between the marker and the second location; and comparing the first distance and the second distance to each other.
The present disclosure also introduces an apparatus comprising: a drill probe assembly configured to be disposed within a borehole extending into a subterranean formation, the drill probe assembly comprising a flexible shaft and a marker; wherein the flexible shaft is configured to drill a hole through a sidewall of the borehole, the hole penetrating the subterranean formation; and wherein the drill probe assembly is configured to dispose the marker within the hole. The flexible shaft may be configured to dispose the marker, at least partially, within the hole. The drill probe assembly may further comprise a plugging piston and a casing plug, wherein the plugging piston is configured to dispose the plug within a through hole formed within casing. The plugging piston may be configured to dispose the marker, at least partially, within the hole. The drill probe assembly may further comprise a moveable carriage configured to move with respect to the subterranean formation. The flexible shaft and the plugging piston may be able to translate in unison with the movable carriage and may be configured to extend from the moveable carriage. The drill probe assembly may further comprise a holder, wherein the holder has the plug and the marker disposed therein. The marker may comprise a radioactive material.
The foregoing outlines feature several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.
The Abstract at the end of this disclosure is provided to comply with 37 C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
Claims
1. A method, comprising:
- positioning a drill probe assembly in a borehole extending into a subterranean formation;
- drilling a hole through a sidewall of the borehole with a flexible shaft of the drill probe assembly, the hole penetrating the subterranean formation; and
- disposing a marker in the hole.
2. The method of claim 1 wherein disposing the marking in the hole comprises using a plugging piston of the drill probe assembly to dispose the marker, at least partially, in the hole.
3. The method of claim 1 further comprising pushing the marker in the hole with the flexible shaft.
4. The method of claim 1 further comprising:
- drilling a through hole into a casing disposed within the borehole with the flexible shaft; and
- disposing a casing plug in the through hole formed in the casing.
5. The method of claim 1 wherein the hole is a first hole, and wherein the marker is a first marker, the method further comprising:
- re-positioning the drill probe assembly in the borehole;
- drilling a second hole through a sidewall of the borehole with the flexible shaft, the second hole penetrating the subterranean formation; and
- inserting a second marker into the second hole.
6. The method of claim 1 wherein casing is disposed within the borehole and cement is disposed, at least partially, within an annulus formed between the casing and the borehole.
7. The method of claim 1 wherein the marker comprises a radioactive material.
8. The method of claim 1 further comprising measuring a distance between the marker and a reference location.
9. The method of claim 8 wherein measuring the distance between the marker and the reference location comprises disposing a measurement tool within the borehole.
10. The method of claim 9 wherein the marker comprises a radioactive material and the measurement tool comprises a gamma radiation detector.
11. The method of claim 8 wherein the hole is a first hole, wherein the marker is a first marker, and wherein the reference location comprises a second marker disposed in a second hole, the second hole penetrating the subterranean formation.
12. The method of claim 8 wherein the distance is a first distance, the method further comprising:
- measuring a second distance between the marker and the reference location; and
- comparing the first distance and the second distance to each other.
13. An apparatus, comprising:
- a drill probe assembly configured to be disposed within a borehole extending into a subterranean formation, the drill probe assembly comprising a flexible shaft and a marker;
- wherein the flexible shaft is configured to drill a hole through a sidewall of the borehole, the hole penetrating the subterranean formation; and
- wherein the drill probe assembly is configured to dispose the marker within the hole.
14. The apparatus of claim 13 wherein the flexible shaft is configured to dispose the marker, at least partially, within the hole.
15. The apparatus of claim 13 wherein the drill probe assembly further comprises a plugging piston and a casing plug, wherein the plugging piston is configured to dispose the plug within a through hole formed within casing.
16. The apparatus of claim 15 wherein the plugging piston is configured to dispose the marker, at least partially, within the hole.
17. The apparatus of claim 15 wherein the drill probe assembly further comprises a moveable carriage configured to move with respect to the subterranean formation.
18. The apparatus of claim 17 wherein the flexible shaft and the plugging piston translate in unison with the movable carriage and are configured to extend from the moveable carriage.
19. The apparatus of claim 15 wherein the drill probe assembly further comprises a holder in which the plug and the marker are disposed.
20. The apparatus of claim 13 wherein the marker comprises a radioactive material.
Type: Application
Filed: Jun 8, 2010
Publication Date: Dec 8, 2011
Inventors: Nathan Church (Missouri City, TX), Peter Fitzgerald (Paris)
Application Number: 12/796,137
International Classification: E21B 47/09 (20060101); E21B 47/01 (20060101);