The invention relates to measuring movement in well equipment for measuring reservoir compaction.
One or more wellbores can be drilled through an earth formation to a reservoir that may contain hydrocarbons or other types of fluid (e.g. water). Completion equipment can then be provided into the one or more wellbores. The completion equipment can be used for extracting fluid from the reservoir and producing the fluid to the earth surface.
As fluid is extracted from the reservoir, reservoir compaction may occur. As fluid is extracted, the reservoir pressure decreases in certain zones of the reservoir, in some cases causing a loss of consolidation and overall compaction of the reservoir. Reservoir compaction is particularly a problem in high permeability reservoirs, or low porosity reservoirs, for example.
Compaction, or other movement of a reservoir can cause deformation of well equipment, such as casing or tubing provided in the wellbore(s), and can lead to failure of such well equipment.
In some cases, well operators attempt to predict the amount of movement that may occur as a result of production from the reservoir. The operators then attempt to modify well equipment to accommodate such movement. However, modifying well equipment designed to accommodate predicted movement of the reservoir is relatively expensive. Also, effective well equipment designed to account for reservoir compaction, for example, requires an accurate prediction of the potential degree of reservoir compaction, which may not be economically feasible or possible.
In general, according to an illustrative embodiment of the present invention, an apparatus for use in a well that extends to a reservoir includes first and second equipment assemblies, and a telescoping connection mechanism between the first and second equipment assemblies. A sensor detects movement in the telescoping connection mechanism to enable measurement of reservoir compaction.
Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
In accordance with some exemplary embodiments of the present invention, a system for use in a well that extends to a reservoir may include well equipment having multiple assemblies connected by a telescoping connection mechanism. A telescoping connection mechanism may be configured to allow for relative axial movement of the first and second equipment assemblies (e.g., along the axial direction of the equipment assemblies and the wellbore). Also, a sensor assembly may be associated with the telescoping connection mechanism in order to detect movement in the telescoping connection mechanism in order to estimate or measure reservoir compaction. Reservoir compaction refers to one or more zones of the reservoir collapsing due to fluid loss and the associated loss of pressure, for example, resulting in an overall reduction of the length of the wellbore extending through the collapsed zones.
The sensor assembly can include one or more sensors, where one sensor is used for detecting movement in the well equipment, while other sensors can measure other properties associated with the wellbore and/or reservoir. As discussed further below, measurements made by such other sensors can also be used as an independent indication or verification of reservoir compaction.
The wellbore 100 depicted in
The first and second casing segments 102, 104 may be connected or coupled to the formation adjacent to the wellbore. If reservoir compaction occurs, one or both of the casing segments 102, 104 may shift as a result of the compaction. This shifting can cause the casing segments 102, 104 to move axially relative to each other at the telescoping connection mechanism 106. Although reservoir compaction is typically described as casing segment 102 moving closer to casing segment 104, embodiments of the current invention may also encompass relative axial movement in which the casing segments 102, 104 move away from each other, as will be readily appreciated by those of skill in the art.
In accordance with some embodiments of the present invention, a sensor assembly 110 may be associated with the telescoping connection mechanism 106. The sensor assembly 110 may be connected to a communications link 112 that extends to well surface equipment 116. The communications link 112 can include an electrical cable, a fiber optic cable, or some other type of link (e.g., wireless link, such as an acoustic link, pressure pulse link, electromagnetic link, etc.). The communications link 112 may pass through the wellhead 114 in order to connect to a controller 118 provided at the well surface.
The controller 118 (which can be implemented with a computer, for example) may be configured to receive measurement data from the sensor assembly 110, and to process the measurement data to provide an indication regarding one or more properties of the wellbore 100 and reservoir 108. The one or more properties can include indications of whether the reservoir 108 has experienced compaction, and the extent of such compaction, for example. Other well or reservoir properties that can be indicated by the controller 118 may include pressure, temperature, and reservoir resistivity, among others.
In the example of
An example of the telescoping connection mechanism 106 is depicted in
Alternatively, the first casing segment 102, second casing segment 104, and the telescoping connection mechanism 106 can be deployed into the wellbore together.
The second connection segment 204 has a portion 205 of reduced diameter relative to the first connection segment 202. As a result, the reduced diameter portion 205 can move axially inside of the first connection segment 202. Each of the first and second connection segments 202 and 204 may be configured to be generally tubular in shape, so that the reduced diameter portion 205 may be substantially concentrically arranged inside (and moveable with respect to) the first connection segment 202.
In some implementations, it may be desirable to run a cable or control line (arranged outside the casing segments 102 and 104) through the telescoping connection mechanism 106. To do so, such a cable or control line can be wound around the outside of the connection segments 202 and 204. In other cases, the communications link may be run along an interior bore or within portions of the casing segments 102, 104 (e.g., such as along the exterior of production tubing, among other methods).
As further depicted in
A biasing element 214, such as a spring, may be provided to push the first connection segment 202 away from the second connection segment 204. However, due to compaction of the surrounding reservoir, the first and second connection members 202 and 204 may overcome the biasing force and be pushed towards each other, or in some cases be pushed further away from each other. Assuming for the purpose of description that the second connection segment 204 (and the second casing segment 104) is fixed in position, then relative movement of the first and second connection segments 202 and 204 will cause relative axial movement of the first connection segment 202, for example. Accordingly, the radial protrusion 208 of the motion detector 206 will move along or across the slanted surface 210 of the profile feature 212. Movement along the slanted surface 210 by the radial protrusion 208 results in radial movement (i.e., displacement) of the radial protrusion 208. The angle of the slanted surface 210 may function to correlate a large axial movement to a relatively limited radial movement.
As depicted in
The motion detector 206 may be configured to detect differences in the radial position of the radial protrusion 208, and to communicate the extent of such radial movement over the communications link 112 (
In another embodiment, the profile feature 112 may be present on the second connection segment 204 and the radial protrusion 208 and motion detector 206 can be provided on the first connection segment 202. In still other embodiments, a motion detector similar to motion detector 206 may directly engage with the first connection segment 202 so that relative movement between the first and second connection segments 202, 204 can be detected.
The motion detector 206 can provide continuous measurement of movement, corresponding to continuous movement of the radial protrusion 208 relative to the slanted surface 210. Such detected continuous movement can be reported continuously to the earth surface controller 118. Alternatively, instead of continuous measurement data, the motion detector 206 can report discrete movement measurements to the controller 118. Even further alternatively, the motion detector 206 may be interrogated either periodically or continuously to report the current position of the radial protrusion 208 or change in position of the radial protrusion 208.
Note that the sensor assembly 110 can include one or more other sensors, such as 216, 218, 220, and so forth. Some of these sensors may be provided as part of the telescoping connection mechanism 106, while other sensors may be provided apart from the connection mechanism 106. The sensors can include pressure sensors, temperature sensors, and resistivity sensors, among others.
The motion detector 206 of
In a different implementation, a position sensor can be implemented using an optical, resistive, electrical, electrostatic, or magnetic mechanism. For example, a position sensor can include an optical detector that uses the Faraday effect, a photo-activated ratio detector, a resistive contacting sensor, an inductively coupled ratio detector, a variable reluctance device, a capacitively coupled ratio detector, a radio wave directional comparator, or an electrostatic ratio detector, among others.
An optical detector can use a position sensing detector to determine the position of an optical probe light that is incident upon a surface of the moveable device. The probe light can be directed to an optically reflective surface that is attached to the moveable member. The laser beam is reflected from the optically reflective surface. The optical detector may be constructed using photodetectors, such as photo-diodes or PIN-diodes, to detect the reflected laser beam.
A capacitance-based position sensor uses a variable capacitor having a value that varies with relative position of a pair of objects. In such systems, the relative position of the objects can be determined by measuring the capacitance.
A magnetic sensor to detect motion typically relies upon permanent magnets to detect the presence or absence of a magnetically permeable object within a certain predefined detection zone relative to the sensor. As one example, the magnetic sensor can be a Hall effect sensor. A Hall effect occurs when a current-carrying conductor is placed into a magnetic field, where a voltage is generated that is perpendicular to both the current and the field. Alternatively, the magnetic sensor can include a magnetoresistive sensor, which uses a magnetoresistive effect to detect a magnetic field. Relative movement of members can be detected based on measured magnetic fields.
The other sensors used to measure other properties can provide additional information to allow for more accurate detection of whether reservoir compaction has occurred. For example, temperature measurement can be used to provide an indication of compaction, since as pressure within a zone of the reservoir lowers, the granular components within the reservoir are forced into closer contact and may ultimately be fused together. Such action lowers the permeability of the zone and may result in a decrease of flow from that zone. Reduced flow will cause a reduction in temperature, which is an indication of possible reservoir compaction. This data in combination with the position sensor used to detect relative movement of different segments of well equipment can be used to confirm that reservoir compaction has occurred.
Note that another possible application of the sensor that is associated with the telescoping connection mechanism 106 is that the sensor assembly 110 can provide an indication that the two different segments of the well equipment have successfully landed into the correct position.
In implementations where the first equipment segment and the second equipment segment are deployed at different times, it may be difficult to provide a wired connection from a sensor of the sensor assembly 110 to the earth surface. In such implementations, as depicted in
Alternatively, instead of using an inductive coupler, acoustic telemetry or electromagnetic (EM) telemetry can be used.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations there from. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.
The following is based on and claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Patent Application Ser. No. 61/013,542 entitled, “METHOD AND APPARATUS TO MEASURE RESERVOIR COMPACTION,” filed on Dec. 13, 2007.
Number | Date | Country | |
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61013542 | Dec 2007 | US |