Method for in SITU wellbore cleaning with dual packer

Abstract

Embodiments presented provide for a method of obtaining an accurate wellbore response using a dual packer system. In embodiments, a wellbore in-situ environment is cleaned prior to obtaining a fluid sample for fluid analysis. The method may include inflating the dual packer to an initial pressure, determining if the dual packer is fully set, and stopping the method when the dual packer is fully set. The method may include measuring a volume of fluid within the dual packer, pumping a fluid in an isolation zone between the dual packer, measuring a volume of the fluid pumped from the isolation zone, measuring a pressure for the dual packer, measuring a pressure interval, and determining if the volume of fluid has reached a threshold and when the volume of fluid has reached the threshold to determine the existence and condition of a mud cake.

Description

METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 603,659, filed November 29, 2023.FIELD OF THE DISCLOSURE

[0002] Aspects of the disclosure relate to downhole fluid sampling. More specifically, aspects of the disclosure provide for a procedure for in-situ clean-up of the wellbore environment to allow for proper zonal isolation and formation testing.BACKGROUND

[0003] In-situ wellbore sampling of fluids is an important component in the hydrocarbon recovery operation industry. In many instances, a series of inflatable bladders (commonly known as packers) are inflated in a wellbore. The space in between the packers is isolated from the remainder of wellbore after the inflation is complete. A probe placed between the packers may then sample the isolation zone fluids to obtain a representative sample from the wellbore. This sampling may lead to many different discoveries related to the wellbore.

[0004] Obtaining a representative sample of the fluid is important to understand the engineering parameters of the downhole environment. Failure to accurately measure the downhole environment may cause engineers to mistakenly assume various features and not maximize wellbore production. Incomplete or incorrect assumptions made by such testing can be expensive for the wellbore owner. Errors, such as missing a hydrocarbon resource layer, can be common, thereby limiting the economic viability of the completed wellbore.

[0005] While the process of creating an isolation zone to obtain a representative sample of the fluid from the wellbore is straightforward, complications may occur in severalMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER instances. One instance is that the integrity of the wellbore “wall” in the downhole environment may not be clearly defined. The wellbore “wall” may actually be encased in mud, thereby preventing accurate seating of the packers to the wellbore “wall”. In such instances, engineers try to seat the packers to the firmest portion of the wellbore as possible to create the isolation zone. Movement of the packers to a more promising position is possible, but not always available.

[0006] In some instances, different types of packer systems are used for creating the isolation zone. In conventional type packer systems, the packers themselves expand in a generally uniform amount in all directions. These conventional packer systems expand similarly to a balloon, expanding an equal amount when filled. In other types of packer systems, the packers are created to expand more in one radial direction than another. These packer systems are defined as asymmetric packer systems. The type of packer system used is important as the specific geometries may not allow for the packer system to be expanded. The expansion may be prevented by the original packer system, especially if the packer system is not properly seated within the wellbore.

[0007] It is important to not only understand the downhole conditions that the packers will experience, but also the downhole conditions must be accurately predicted prior to placement into the wellbore. Placement of the wrong type of packer system into the wellbore will necessitate removal of the packer system. The removal of a packer system from the downhole environment is a costly economic endeavor that would be advantageous to avoid. If difficulties exist with an existing packer system placement, an alternative plan may be to “move” the packer system to another area within the wellbore system in order to avoid reworking the packer system.

[0008] Prior to resetting a packer system into a secondary position to establish an isolation zone, mud (generally called “mud cake”) may accumulate on the outside of theMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER packers. The mud cake may inhibit movement of the packer system, as well as cause deflation of an inflated system. Mud cake; therefore, can become a significant issue in establishing a correct isolation zone.

[0009] Conventionally, there is no ability to rectify mud cake problems with conventional packer systems. When mud cake problems are encountered, engineers cannot accurately determine all necessary downhole parameters. Conventional activities are merely related to replacement of the packer system into another position within the wellbore by “squishing” the packer system into the mud and hoping that the new position allows for conditions for proper sampling. As previously described, in other instances, the packer system is removed from the wellbore environment altogether and replaced with another packer system.

[0010] There is a need to provide an isolation zone in a wellbore in all types of wellbore environments, including mud. The provision of such an isolation zone should be performed by an originally selected packer system without the need for rework of wellbore systems.

[0011] There is a further need to provide a method that may be utilized for both conventional symmetrical packers as well as unidirectional packers to establish the isolation zone.

[0012] There is a further need to avoid wellbore conditions that would be detrimental to packer performance or packer life, such as mud cake.

[0013] There is a further need to be able to clean the formation around a wellbore such that formation response is accurate.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER

[0014] There is a further need to be able to avoid debris, including mud cake, in the downhole environment that may impede obtaining accurate formation readings.

[0015] There is a further need to be able to more accurately measure downhole parameters and avoid economic costs associated with conventional apparatus difficulties experienced in mud cake environments.SUMMARY

[0016] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized below, may be had by reference to embodiments, some of which are illustrated in the drawings. It is to be noted that the drawings illustrate only typical embodiments of this disclosure and are; therefore, not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments without specific recitation. Accordingly, the following summary provides just a few aspects of the description and should not be used to limit the described embodiments to a single concept.

[0017] In one non-limiting embodiment, a method for in-situ wellbore cleaning with a dual packer is disclosed. The method comprises inflating the dual packer to an initial pressure. The method further comprises determining if the dual packer is fully set. The method further comprises stopping the method when the dual packer is fully set. The method further comprises measuring a volume of fluid within the dual packer. The method further comprises pumping a fluid in an isolation zone between the dual packer. The method further comprises measuring a volume of the fluid pumped from the isolation zone. The method further comprises measuring a pressure for the dual packer. The method further comprises measuring a pressure interval. The method further comprises determining if the volume of fluid has reached a threshold and when the volume of fluidMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER has reached the threshold, determining a presence of mud cake being opened around the dual packer and inflating the dual packer to the initial pressure setting. The method further comprises determining a presence of mud cake sealing and conducting packer rubbing when the pumped volume threshold has not been reached. The method further comprises determining if the packer pressure has reached a threshold, and when the packer pressure has not reached the threshold, determining that the mud cake has opened around the dual packer, and when the dual packer pressure has reached the threshold, then conducting dual packer rubbing. The method further comprises, after the measuring of the dual packer pressure or monitoring the interval pressure, calculating mud cake properties, interpreting mud cake removal and determining when the mud properties are stable. The method further comprises inflating the dual packer to the initial setting pressure and inflating the dual packer to a higher pressure setting and continuing the method at a step of determining if the packer is fully set.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the drawings. It is to be noted; however, that the appended drawings illustrate only typical embodiments of this disclosure and are; therefore, not be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0019] FIG. 1 is a method for cleaning a wellbore in one non-limiting embodiment of the disclosure.

[0020] FIG. 2 is a series of cross-sections of a prior art downhole apparatus during a process of packer inflation.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER

[0021] FIG. 3 is a series of cross-sections of a prior art downhole apparatus during a process of packer sealing with a wellbore.

[0022] FIG. 4 is a graph of pressure for a packer system during a series of pressure variations.

[0023] FIG. 5 is a graph of pressure for a packer system during a series of pressure variations.

[0024] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures (“FIGS”). It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.DETAILED DESCRIPTION

[0025] In the following, reference is made to embodiments of the disclosure. It should be understood; however, that the disclosure is not limited to specific described embodiments. Instead, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement and practice the disclosure. Furthermore, although embodiments of the disclosure may achieve advantages over other possible solutions and / or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the disclosure. Thus, the following aspects, features, embodiments and advantages are merely illustrative and are not considered elements or limitations of the claims except where explicitly recited in a claim. Likewise, reference to “the disclosure” shall not be construed as a generalization of inventive subject matter disclosed herein and should not be considered to be an element or limitation of the claims except where explicitly recited in a claim.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER

[0026] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, components, region, layer or section from another region, layer or section. Terms such as “first”, “second” and other numerical terms, when used herein, do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed herein could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0027] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, coupled to the other element or layer, or interleaving elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no interleaving elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed terms.

[0028] Some embodiments will now be described with reference to the figures. Like elements in the various figures will be referenced with like numbers for consistency. In the following description, numerous details are set forth to provide an understanding of various embodiments and / or features. It will be understood; however, by those skilled in the art, that some embodiments may be practiced without many of these details, and that numerous variations or modifications from the described embodiments are possible. As used herein, the terms “above” and “below”, “up” and “down”, “upper” and “lower”, “upwardly” and “downwardly”, and other like terms indicating relative positions above orMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER below a given point are used in this description to more clearly describe certain embodiments.

[0029] Aspects of the disclose provide a method that may be used to clean a wellbore from debris during downhole operations. The debris may include mud cake. In embodiments, a dual packer arrangement is a component that is used during the method described. The dual packer arrangement may be intended to be used to isolate a wellbore zone for sampling, as may be a common need for the hydrocarbon recovery industry. In order to achieve accurate results, embodiments of the disclosure provide for improved packer and formation response compared to conventional apparatus.

[0030] In aspects of the disclosure, the inflation of the packers within the dual packer arrangement is metered during the inflation periods and deflation periods. One aspect of the disclosure comprises metering the inflation of the packer, prior to the packer reaching a fully set condition, and, in essence, circulating fluid over the choked annulus, prior to setting the packer. In embodiments, aspects of the disclosure provide a paradigm shift, thereby utilizing asymmetrical packers in the direction they are designed to work, hence preserving the packer sealing integrity or preventing compromises in the packer design and pressure rating.

[0031] In aspects of the disclosure, conducting cleaning of the downhole environment around the packer is necessary. Cleaning of the formation in-situ improves performance and sharpens any generated pressure signature for a more accurate formation evaluation response.

[0032] As described above, conventionally, the cleaning practice consists of “squishing” the packer into the mud to hopefully improve sealing contact between the packer system and the wellbore wall. The amount of contact may be augmented (improved) by removalMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER of fluid from the downhole environment, allowing a seating of the packer system. For example, water (and potentially mud) is sucked into an orifice within the packer system and expelled from another orifice. As can be understood, a side with a loose sealing and excessive mud may be “drained” from a particular portion of the packer system and deposited into another portion of the wellbore. This procedure may be insufficient in some environments where mud cake is thick and could have consequences on data quality (pressure signature of formation response to differential pressure across the packer).

[0033] The process of fracturing, in some instances, intends to involve cleaning a wellbore from mud. The technique entails exercising the packer in a reverse direction (applying differential pressure in the opposite direction to that sought for formation evaluation) upon setting to better seat the packer against the borehole wall. Although this technique bears some advantage regarding better seating the packer in the mud, it still appears non-optimal in many respects to optimize the contact of the packer with the formation.

[0034] It should be noted that most dual packers used by the industry for formation evaluation are asymmetrical, for the unidirectionality allows integration of design features that can withstand higher differential pressure loads on a specific side (aka low-pressure side) while other design features are implemented on the other side (aka high-pressure side) to preserve integrity of rubber bonding to the packer end. Symmetrical packers; however, are significantly different. A symmetrical packer requires a resistance to both compression and tensile forces, unlike unidirectional packer systems; therefore, higher differential pressure loads on a specific side (the low-pressure side) and the other side of the packer system are not performed.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER

[0035] The use of pressure reversal is avoided as such pressure reversal would impede on the packer performance in terms of pressure rating or life (comparatively more premature failure than in the most standard case of asymmetrical packers).

[0036] Aspects of the disclosure herein provide for bringing the packer near to a contact with the borehole and using the pumping capability within the packer interval to expel drawn in mud in the direction normally allowed by the unidirectional packer design. Aspects of the disclosure avoid making any of the above-listed compromises to the packer specification and possible packer degradation. Thus, in embodiments, sampling of fluids or fracturing may be performed. In the specific case of fracturing in the downhole environment, another significant advantage of the disclosure arises as the mud that is circulated over the packer outer diameter is filtered through the tool string before being injected in the interval, hence clean fluid is used for wellbore cleaning.

[0037] Referring to FIG. 2, a series of conventional packer inflation steps are illustrated for general information. In the top portion of FIG. 2, the packer is seen in a deflated condition. In this state, the packer may be connected to the remainder of the wellbore tool string and inserted into the wellbore. Once in the wellbore at the appropriate elevation, the second state shown in FIG. 2 shows a partial inflation of the packer to a fifty pounds per square inch level. As can be seen, an inflation volume in an area of a thinner construction inflates first. Thus, the left most portion of the packer and the right most portion of the packer inflate first. In the third step, inflation continues to a five hundred pounds per square inch level. At this full inflation level, it can be seen that the packer is straight across on the horizontal plane and packer skin is allowed to abut the formation.

[0038] Referring to FIG. 3, a series of conventional packer inflation steps for packer sealing to a wellbore environment is disclosed. In the top portion of FIG. 3, the packerMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER system is shown in a deflated condition. In the second portion of FIG. 3, the packer system is shown at a five hundred pounds per square inch inflation. In the third portion of FIG. 3, the packer system is inflated to full pressure when interval sealing pressure extends across the full length of contact for the inflatable portions of the packer system. Overinflation is prevented by use of a cable preventing extrusion.

[0039] Aspects of the method of the current disclosure are presented in relation to FIG. 1 . The method 100 may be used to provide for accurate sealing of a packer system to a formation. The procedure is started at 101 where the method 100 branches into two steps, namely determination if an asymmetrical dual packer is used at 105 and if there is a suspicion of mud cake within the borehole at 103. As will be understood, before the first inflation, the packer may naturally be considered “not set” and the process may default to initial circulation of mud, if appropriate, to set a mud property baseline. With answers to steps 103 and 105, the method proceeds to inflation of the packer system to an initial pressure setting at 107. After inflation to the initial pressure setting at 107, a check is done to determine if the packer is fully set at 111. If the packer is fully set, the method proceeds to conducting a downhole operation at 141 , such as sampling of fluid from the downhole environment or conducting a hydraulic fracturing operation. The method may end after the conclusion of the downhole operation at 141.

[0040] In the instance at 111 that the packer is not fully set, the method continues in measuring a packer volume of inflation fluid within the packer system at 113. After 113, the method proceeds to both calculation of mud cake properties at 123 and pumping fluid to / from the isolated interval defined by the packers at 115. After 115, the method continues with three method steps including measuring the pumped volume at 117, measuring packer pressure at 119 and monitoring an interval pressure 121 for the packer system. After measuring the pumped volume at 117, measuring the packer pressure atMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER119 and monitoring the interval pressure 121 , the method progresses to calculating mud cake properties at 123.

[0041] In addition to the proceeding to calculating mud cake properties 123 from the measurement of the pumped volume 117, the method further progresses to determining if a pumped volume threshold has been met at 131. If the pumped volume threshold has been met, the mud cake is calculated to be opened and packer chocking has occurred at 135. The method continues from 135 to inflating the packer to an initial setting pressure at 139 and the method returns at 133 to inflating the packer to a higher pressure setting at 109, eventually to the query at 111 to determine if the packer is set. If the pumped volume threshold has not been met at 131, the method proceeds to a determination that mud cake sealing is occurring and there is packer rubbing at 137. After this determination, the method continues to 139 of inflating the packer to an initial setting pressure at 139.

[0042] If, at 129, the packer pressure threshold is not met, then the method proceeds to 135 for determining that the mud cake is calculated to be opened and packer chocking has occurred at 135. If the packer pressure threshold is met at 129, then the method proceeds to a determination that there is mud cake sealing and packer rubbing is occurring at 137, followed with inflating the packer to an initial setting pressure at 139.

[0043] From 123, the method progresses to interpreting that mud cake removal is required at 125 followed by determination of stable mud properties at 127. If the mud properties are stable at 127, the method proceeds to inflating of the packer to an initial setting pressure at 139.

[0044] It should be noted that the method 100 is the only possible to offer a gentle, cleaning option for the wellbore. As will be understood, alternative mechanical debris removal methods may easily be envisioned; however, such methods will bear theMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER disadvantage of damaging the very surface that is subsequently used to provide the seal. For example, mechanically dragging a packer assembly along the side of a wellbore to “clean the outside” of the packer assembly will exert forces on the packer system that are unintended in the design of the packer system, thereby damaging the packers. To this end, scraping the sides of the packer system along the wellbore is detrimental to the components used.Specific Tool / Method Application

[0045] As described in relation to FIG. 1 , the principle of mud cake removal may be accomplished quickly and efficiently. As described, the method 100 proceeds in several steps of inflation during the inflation method to encourage displacement of the mud cushion away from the packer setting location, through various means of interaction that engage depending on the mud cake properties. Indirect measurement of mud cake properties at station (e.g. measuring location) may be inferred with this method to provide quality control on the packer setting properties.Detailed Aspects of the Technique

[0046] The method 100 uses three modes of interaction with the mud:■ Squishing. That is the simplest and most widespread method exercised of removing the mud cake for it naturally occurs as the packer is being set.■ Rubbing. That is the method implemented with symmetrical packers.■ Circulating. That consists in properly choking the flow with the packer and forcing the mud cake to displace sideways under hydraulic pressure.

[0047] It should be understood that aspects of the disclosure handle the mechanical rubbing at 137 differently: As the packer is not completely inflated, the packer will deformMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER further from a rectangular to a more square cross-section profile (preserving the internal volume) under interval differential pressure, which favors the ejection of mud. Also, the loading of the packer against mud cake being controlled at each cycle, less friction load (and concurrent skin damage) will be encountered. Both the larger displacement and the lower friction multiply the efficiency of the rubbing action from prior art methodology.

[0048] As will be understood, the mud cake gets more easily removed by some wiping action on the outside of the packers rather than squishing (displacing the mud particles in the direction orthogonal to the load that causes the cake to form and remain in position).

[0049] As will be understood, although a natural sequence of events may include squishing, then rubbing, then circulating, aspects of the disclosure provide that all three modes of mud removal work concurrently and not independently. Hydraulic and mechanical effects act together, taking advantage of the packer as a flexible membrane, to adjust and deform and thereby distribute the load on the mud cake. Similarly, should inconsistency exist in the mud cake structure, a portion of the mud cake may be removed by circulation (preventing further clean-up by the opening of a flow path between interval and hydrostatic). In embodiments, squishing will contribute to homogenize the mud cake in the next inflation cycle. The clean-up method, as disclosed herein, does not aim at controlling a specific clean-up mode but at taking maximum advantage of the packer nature to achieve the best result possible.

[0050] In embodiments, a limit is placed on potential pumped volumes to prevent losing too much time on one cycle. Such limits allow for increased efficiency because, in some instances, a simple reset of the packer may increase efficiency in the immediately following cycle. In further embodiments, a pressure limit is also introduced to prevent mechanical rubbing damage to the packer that is not originally designed for this type of application.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKERAlternate Embodiments

[0051] As will be understood, mud removal from exterior surfaces may not be perfect. In some instances, complete mud cake removal will cause differential pressure sticking concerns. In some embodiments, as a safety precaution, an active retraction mechanism, or vacuum chamber to retract the packer out of station, may be used to mitigate differential sticking and help with retraction. Such configurations will allow a higher circulation pressure at a reduced contact pressure with mud cake.

[0052] Success in implementing the method described is at least partly reliant on the selection of the initial setting pressure and the setting pressure increments (that may or may not be constant). Mud cake & borehole setting geometries vary greatly from well to well and even from station to station within the same hole. In this condition, the reaction of the mud cake to the mechanical and hydraulic solicitations may be processed to adjust the parameter on the next cycle.

[0053] Packer design and configuration parameters will influence the cleaning mode exercised in the method described. The thickness of the packer skin, for example, will control the packer stretching pressure to come in contact with the mud cake, such that the initial setting pressure is established to warrant initial contact. The profile of the external skin may be designed to foster rubbing movement (such as in the illustration of contact pressure loss below). Packers may also be assembled with or without an Active Retraction Mechanism and it should be considered that, through those assemblies, the stretching pressure of the packer will be linearly increased against hydrostatic pressures.

[0054] In embodiments, the packer assembly on mandrel requires both a fixed end and a sliding end. This construction influences how each packer reacts under interval pressure increases. In a typical assembly; however, one packer has a fixed end withinMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER the interval and the other packer has a sliding end within the interval. With this configuration; therefore, although the individual packer movement may be different in this context, contact pressure of the packer against the mud cake will remain equal on both.

[0055] Referring to FIGS. 4 and 5, graphs of pressure for dual packer system are illustrated. As can be seen, pressure may vary according to different steps related to the method performed, related to FIG. 1.

[0056] Example embodiments will next be disclosed. In one non-limiting embodiment, a method for in-situ wellbore cleaning with a dual packer is disclosed. The method comprises inflating the dual packer to an initial pressure. The method further comprises determining if the dual packer is fully set. The method further comprises stopping the method when the dual packer is fully set. The method further comprises measuring a volume of fluid within the dual packer. The method further comprises pumping a fluid in an isolation zone between the dual packer. The method further comprises measuring a volume of the fluid pumped from the isolation zone. The method further comprises measuring a pressure for the dual packer. The method further comprises measuring a pressure interval. The method further comprises determining if the volume of fluid has reached a threshold and when the volume of fluid has reached the threshold, determining a presence of mud cake being opened around the dual packer and inflating the dual packer to the initial pressure setting. The method further comprises determining a presence of mud cake sealing and conducting packer rubbing when the pumped volume threshold has not been reached. The method further comprises determining if the packer pressure has reached a threshold and when the packer pressure has not reached the threshold, determining that the mud cake has opened around the dual packer and when the dual packer pressure has reached the threshold, then conducting dual packer rubbing. The method further comprises after the measuring of the dual packer pressure or monitoring the interval pressure, calculating mud cake properties, interpreting mud cake removal and determining when the mud properties are stable. The method furtherMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER comprises inflating the dual packer to the initial setting pressure and inflating the dual packer to a higher pressure setting and continuing the method at a step of determining if the packer is fully set.

[0057] In another example embodiment, the method may further comprise conducting a sampling operation in the isolation zone between the dual packers after the packer is fully set.

[0058] In another example embodiment, the method may further comprise conducting a hydraulic fracturing operation after the packer is fully set.

[0059] In another example embodiment, the method may further comprise determining a presence of an asymmetrical configuration for the dual packer at a start of the method.

[0060] In another example embodiment, the method may be performed wherein the measuring of the packer volume is conducted through monitoring of an internal pump within the dual packer.

[0061] In another example embodiment, the method may be performed wherein the pumping of the fluid in the interval is away from the interval.

[0062] In another example embodiment, the method may be performed wherein the pumping of the fluid in the interval is into the interval.

[0063] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be usedMETHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER in a selected embodiment, even if not specifically shown or described. The same may be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0064] While embodiments have been described herein, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments are envisioned that do not depart from the inventive scope. Accordingly, the scope of the present claims or any subsequent claims shall not be unduly limited by the description of the embodiments described herein.

Claims

METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKERCLAIMSWhat is claimed is:1 . A method for in-situ wellbore cleaning with a dual packer, comprising: inflating the dual packer to an initial pressure; determining if the dual packer is fully set; stopping the method when the dual packer is fully set; measuring a volume of fluid within the dual packer; pumping a fluid in an isolation zone between the dual packer; measuring a volume of the fluid pumped from the isolation zone; measuring a pressure for the dual packer; measuring a pressure interval; determining if the volume of fluid has reached a threshold and when the volume of fluid has reached the threshold, determining a presence of mud cake being opened around the dual packer and inflating the dual packer to the initial pressure setting; and determining a presence of mud cake sealing and conducting packer rubbing when the pumped volume threshold has not been reached; determining if the packer pressure has reached a threshold and when the packer pressure has not reached the threshold, determining that the mud cake has opened around the dual packer and when the dual packer pressure has reached the threshold, then conducting dual packer rubbing; and after the measuring of the dual packer pressure or monitoring the interval pressure, calculating mud cake properties, interpreting mud cake removal and determining when the mud properties are stable; and inflating the dual packer to the initial setting pressure and inflating the dual packer to a higher pressure setting and continuing the method at a step of determining if the packer is fully set.METHOD FOR IN SITU WELLBORE CLEANING WITH DUAL PACKER2. The method according to claim 1 , further comprising conducting a sampling operation in the isolation zone between the dual packers after the packer is fully set.

3. The method according to claim 1 , further comprising conducting a hydraulic fracturing operation after the packer is fully set.

4. The method according to claim 1 , further comprising determining a presence of an asymmetrical configuration for the dual packer at a start of the method.

5. The method according to claim 1 , wherein the measuring of the packer volume is conducted through monitoring of an internal pump within the dual packer.

6. The method according to claim 1 , wherein the pumping of the fluid in the interval is away from the interval.

7. The method according to claim 1 , wherein the pumping of the fluid in the interval is into the interval.

8. The method as illustrated and described.

9. The apparatus as illustrated and described.

10. The method according to claim 1 , comprising inflating the dual packer for a set time.

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