The present disclosure relates generally to systems and methods for removing filter cake from a subterranean wellbore and, more particularly, to the removal of filter cake from specified intervals subsequent to installing a lower completion assembly in the wellbore.
A drill bit at a lower end of a drill string is often advanced through a geologic formation to form a subterranean wellbore. A drilling fluid or “mud” is circulated down the drill string, out through nozzles in the drill bit and returned to the surface through an annulus defined between the drill string and a wall of the wellbore. The circulation of drilling fluid cools the drill bit and carries geologic cuttings from the wellbore. During drilling operations, some of the drilling fluid may be lost into the surrounding geologic formation. To prevent these losses, a drilling fluid may be modified such that a small portion of the fluid, and any solids carried by the drilling fluid, form a coating on the wellbore wall, i.e., a filter cake.
Once the drilling operations are complete, the filter cake is removed to permit hydrocarbons or other targeted fluids to flow into the wellbore from the geologic formation. The wall of the wellbore may be washed with suitable fluids to dissolve or dislodge the filter cake, and subsequently, a lower completion including valve screens may be installed to receive the targeted fluids and facilitate production to the surface. Failures may occur in the installation of the lower completion that result in the lower completion becoming lodged in the wellbore. The accumulation of filter cake on the wellbore walls may make retrieval of the lower completion difficult in these failed installations. Even in successful installations, filter cake remaining on the wellbore wall may hinder the production of the targeted fluids through the lower completion.
Various details of the present disclosure are hereinafter summarized to provide a basic understanding. This summary is not an extensive overview of the disclosure and is neither intended to identify certain elements of the disclosure, nor to delineate the scope thereof. Rather, the primary purpose of this summary is to present some concepts of the disclosure in a simplified form prior to the more detailed description that is presented hereinafter.
According to an embodiment consistent with the present disclosure, a method for removing filter cake from a subterranean wellbore includes (a) running a completion string into the wellbore on a string of production tubing, wherein the completion string includes one or more screen assemblies coupled therein, (b) conveying a running tool through the production tubing until the running tool reaches a shifting tool coupled within the completion string, (c) opening a circulation port of the shifting tool with the running tool, (d) flowing a spotting fluid through the running tool to and the shifting tool, (e) discharging the spotting fluid from the completion string into the wellbore, (f) interacting the spotting fluid with the filter cake to remove the filter cake from a wall of the wellbore and (g) circulating the spotting fluid through the circulation port.
In another embodiment, a system for removing filter cake from a subterranean wellbore includes a string of production tubing extending into the wellbore, a completion string defined at a lower end of the production tubing, a shifting tool coupled within the completion string and a running tool at a lower end of a conveyance extending through the string of production tubing. The completion string includes one or more screen assemblies coupled therein. The shifting tool includes a circulation port extending between a central flow channel and an exterior of the shifting tool and a sleeve assembly selectively movable within the central flow channel between a first longitudinal position wherein the circulation port is obstructed and a second longitudinal position wherein the circulation port is closed. The running tool is selectively operable to move the sleeve assembly between the first and second longitudinal positions and to deliver a spotting fluid from the conveyance through the shifting tool.
Any combinations of the various embodiments and implementations disclosed herein can be used in a further embodiment, consistent with the disclosure. These and other aspects and features can be appreciated from the following description of certain embodiments presented herein in accordance with the disclosure and the accompanying drawings and claims.
Embodiments of the present disclosure will now be described in detail with reference to the accompanying Figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the claimed subject matter. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. Additionally, it will be apparent to one of ordinary skill in the art that the scale of the elements presented in the accompanying Figures may vary without departing from the scope of the present disclosure.
Embodiments in accordance with the present disclosure generally relate to the removal of filter cake from specified intervals subsequent to installing a lower completion assembly in a wellbore. The removal of filter cake subsequent to installing the lower completion assembly may facilitate dislodging a stuck lower completion assembly and may also promote production of targeted fluids through the wellbore.
A string of production tubing 112 may be positioned within the wellbore 102 and extend from a well surface location (not shown), such as the Earth's surface. The production tubing 112 provides a conduit for fluids extracted from the formation 110 to travel to the well surface location for production. A hanger 113 is provided between the production tubing and the casing 108. The hanger 113 may be carried by the production tubing 112 and may include radially expandable teeth or other structures that bite into the casing 108 to hold the production tubing 112 in place.
A completion string 114 may be coupled to or otherwise form part of the lower end of the production tubing 112 and arranged within the horizontal section 106. The completion string 114 may be configured to divide the wellbore 102 into various production intervals or “zones” adjacent the subterranean formation 110. To accomplish this, as depicted, the completion string 114 may include a plurality of inflow control devices or “ICDs” 116 axially offset from each other along portions of the production tubing 112. In some embodiments, each inflow control device 116 may be positioned between a pair of wellbore packers 118 that provides a fluid seal between the completion string 114 and the inner wall of the wellbore 102, and thereby defining discrete production intervals or zones.
The inflow control devices 116 are operable to selectively regulate the flow of fluids 120 into the completion string 114 and, therefore, into the production tubing 112. In the illustrated embodiment, each inflow control device 116 includes a sand control screen assembly 122 that filters particulate matter out of the formation fluids 120 originating from the formation 110 such that particulates and other fines are not produced to the well surface location. After passing through the sand control screen assembly 122, the inflow control devices 116 may be operable to regulate the flow of the fluids 120 into the completion string 114. Regulating the flow of fluids 120 into the completion string 114 from each production interval may be advantageous in preventing water coning 124 or gas coning 126 in the subterranean formation 110. Other uses for flow regulation include, but are not limited to, balancing production from multiple production intervals, minimizing production of undesired fluids, maximizing production of desired fluids, etc.
As used herein, the term “fluid” or “fluids” (e.g., the fluids 120) includes liquids, gases, hydrocarbons, multi-phase fluids, mixtures of two of more fluids, water and fluids injected from the surface, such as water. Additionally, references to “water” includes fresh water but should also be construed to also include water-based fluids; e.g., brine or salt water. In accordance with embodiments of the present disclosure, the inflow control devices 116 may have a number of alternative structural features that provide selective operation and controlled fluid flow there through.
It should be noted that even though
Furthermore, while
A shifting tool 130 is provided within the completion string 114 to deploy a filter cake remover 132 (see
A plurality of circulation ports 160 extend radially between the central flow channel 154 and the exterior of housing 152. In other embodiments, the circulation ports 160 may be defined through a separate housing (not shown) or directly through a wall of the base pipe 140. In
The sleeve assembly 162 includes a shifting sleeve 164 having a longitudinal flow passage 166 defined therethrough. A latching profile 168 may be defined in the shifting sleeve 164 at an upper end of the longitudinal flow passage 166 such that both upward and downward forces may be applied to the sleeve assembly 162 by a running tool 170 (see
The sleeve assembly 162 also includes a plurality dogs or “latch members” 176 circumferentially spaced around the shifting sleeve 164. The latch members 176 are biased to a radially outward position with respect to the shifting sleeve 164 by respective biasing members 178. The biasing members 178 may include helical compression springs, Belleville washers, wave washers and/or similar structures. The latch members 176 may be circumferentially (angularly) offset from the circulation ports 160 such that the latch members 176 engage an inner diameter 180 of the shifting sleeve 164 and are prevented from extending into the circulation ports 160.
The inner diameter 180 is profiled to receive the latch members 176 in at least a lower groove 182 and an upper groove 184. In at least one embodiment, the lower and upper grooves 182, 184 may extend a full circumference around the sleeve assembly 162, but in other embodiments, the upper and lower grooves 182, 184 may be segmented to extend only at circumferential positions corresponding to the circumferential positions of the latch members 176. The lower groove 182 is longitudinally positioned along the base pipe 140 such that when the latch members 176 are received therein, the shifting sleeve 164 does not obstruct the circulation ports 160, as shown in
In some embodiments, the lower groove 182 may include an upper chamfered surface or taper 186 corresponding to an angled surface 188 of the latch members 174. The angled surfaces 188 of the latch members 176 may engage the upper taper 186 of the lower groove 182 when the latch members 176 are received in the lower groove 182 (see
Referring now to
The well system 200 includes a string of production tubing 112 carrying various components together in a completion string 206. The completion string 206 generally includes a radially extendable hanger 113 at an upper end thereof, a circulation valve 208, a pair of open-hole packers 210, an upper packer 118a, a shifting tool 130, a lower packer 118b and a pair of lower sand control sleeve assemblies 122. The completion string 206 may be lowered into the wellbore 208 on the production tubing 112 until the open-hole packers 210 enter the open-hole section 204 and the hanger 113 remains within the casing 108.
Next, as illustrated in
Next, cement 214 may be pumped thorough the production tubing 112 and may be discharged through the circulation valve 208 as illustrated in
As illustrated in
Running tool 170 may then be run into the wellbore 202 toward the shifting tool 130 as illustrated in
As illustrated in
The spotting fluid 224 may include any fluid composition that may be useful in subterranean applications for addressing, for example, drill string sticking difficulties. Oil-based muds may traditionally be used as spotting fluids, but surfactants and other cleaning solutions are contemplated for use as spotting fluid 224. The spotting fluid 224 may be delivered through the conveyance 222 to the shifting sleeve 164. The spotting fluid 224 continues through the longitudinal flow passage 166 of the shifting sleeve 164 and through the remainder of the completion string 206 where it may be discharged through a lowermost one of the sand control sleeve assemblies 122 and/or an opening 226 defined at the lower end of the completion string 206. The spotting fluid 224 may fill the open-hole section 204 below the cement 214 and pass through the circulation ports 160 to enter the production tubing 112. The spotting fluid 224 may then flow upward to the surface location through an annulus 228 defined between the conveyance 222 and the production tubing 112. The spotting fluid 224 may interact with the filter cake 136 and remove the filter cake 136 from the open-hole section 204 of the wellbore 202. The spotting fluid 224 may dislodge, dissolve or otherwise remove the filter cake 136 from the wall of wellbore 202.
As illustrated in
Referring now to
Next, as illustrated in
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, for example, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “contains”, “containing”, “includes”, “including,” “comprises”, and/or “comprising,” and variations thereof, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Terms of orientation are used herein merely for purposes of convention and referencing and are not to be construed as limiting. However, it is recognized these terms could be used with reference to an operator or user. Accordingly, no limitations are implied or to be inferred. In addition, the use of ordinal numbers (e.g., first, second, third, etc.) is for distinction and not counting. For example, the use of “third” does not imply there must be a corresponding “first” or “second.” Also, if used herein, the terms “coupled” or “coupled to” or “connected” or “connected to” or “attached” or “attached to” may indicate establishing either a direct or indirect connection, and is not limited to either unless expressly referenced as such.
While the disclosure has described several exemplary embodiments, it will be understood by those skilled in the art that various changes can be made, and equivalents can be substituted for elements thereof, without departing from the spirit and scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation, or material to embodiments of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, or to the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.
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6725929 | Bissonnette | Apr 2004 | B2 |
8757273 | Themig et al. | Jun 2014 | B2 |
8991505 | Fleckenstein et al. | Mar 2015 | B2 |
20180258738 | Lan | Sep 2018 | A1 |
Number | Date | Country |
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3135858 | Feb 2018 | EP |