Patent Description:
A deployment of an electrical submersible pump in an oil or water well is common practice. Additionally, the use of an associated bypass-system is well known. The bypass system was designed to allow access to a well below an electrical submersible pump assembly in order that logging and/or well intervention operation could be performed without the removal of the completion, thus enabling work to be carried out under dynamic well conditions. Continual development of the system has maximized the operational benefits and includes permanent downhole monitoring of the well parameter and electrical submersible pump performance using the multi sensor system.

Bypass systems are available for an extensive range of casing weights and can be supplied to suit all well environments, using a wide range of materials to suit individual well chemistry and being internally coated to provide added protection and reduce friction as required. Each bypass system is individually designed to provide the optimum completion, affording full protection to the electrical submersible pump power cable and auxiliary service lines whilst providing uninterrupted access to the well below the electrical submersible pump.

Bypass-systems usually comprise a Y-Tool. The Y-Tool provides the facility by which the electrical submersible pump assembly is deployed with bypass tubing to allow access to the well in order that logging and/or intervention work may be carried out below without retrieval of the completion. The Y-Tool provides a single connection to the production string above and has a bypass connection below directly in line with the production string to allow the passage of logging tools to the well below via the bypass Tubing. The Y-tool comprises a fluid tubing and a further fluid tubing in which the electrical submersible pump is arranged.

A further connection at the base of the Y-Tool allows the electrical submersible pump assembly to be suspended. The Y-Tool has a groove on either side to allow the passage of the electrical submersible pump power cable, or other auxiliary service lines. These umbilicals are secured in the Y-Tool groove with clips thus ensuring full protection during deployment. The internal profile of the Y-Tool is designed to ensure a smooth flow path from electrical submersible pump discharge to production tubing.

Bypass-systems are designed and built to suit specific well completion. A well completion can be for example a cleanout logging operation and/or a means of running downhole samplers below the electrical submersible pump on horizontal reservoir sections. For performing such operations a coiled tubing logging plug is used.

The coiled tubing logging plug can be deployed in all standard bypass systems and is used as a means of sealing between the fluid tubing, in particular a tubing nipple bore, and the coiled tubing outside diameter. The plug can be used for various combinations of coiled tubing strings and tubing nipple sizes. It is utilized successfully for clean out operations, production logging runs and also as a means of running downhole samplers below the electrical submersible pumps on horizontal reservoir sections.

The plug is attached to the coiled tubing string via a retaining sleeve and collets, the latter being activated to a release position on engagement of the tubing nipple profile.

On release of the retaining sleeve from the holding collets the plug is automatically locked in the nipple profile. The plug cannot be released prior to engagement in the nipple. Once locked in place the plug can only be released or unseated if the retaining sleeve or sleeve is pulled into the plug from below and pin is sheared and/or a bottom crossover shoulders the bottom edge of the collet lock on the coiled tubing plug. This aligns up the collet locking fingers with the groove in the sleeve allowing them to collapse and to unseat. Only if the tool string is pulled into the plug will it be unseated.

When cleanout/logging operations are complete the electrical submersible pump is switched off, and after a short period to allow equalization across the pump, the tool string is pulled out of the hole. As the tool string with retaining sleeve or sleeve or crossover engages the bottom of the plug, a pin is sheared and/or the bottom crossover shoulders the bottom edge of the collet lock on the coiled tubing plug and in turn allows the locking mechanism to collapse and the plug to be retrieved to surface along with the tool string.

If the coiled tubing logging plug cannot be removed from the fluid tubing of the bypass system, it is not possible to continue with the fluid extraction from the well. It is necessary to remove the coiled tubing logging plug as otherwise a self-circulation situation occurs in which the fluid is pumped within the bypass-system. This can lead to self-circulating problems and, thus, to a damage of the electrical submersible pump.

In such situations it is known to stop the fluid extraction and exchange the bypass-system including the stuck coiled tubing logging plug. Said operation leads to high costs for the company due interrupting the fluid extraction.

The object of the invention is to reduce the costs for situations in which the coiled tubing logging plug cannot be removed from the fluid tubing.

The object is solved by a sealing tool for downhole sealing of a coiled tubing logging plug, wherein the sealing tool comprises a sealing body that is configured to be removably insertable into a through-hole of the coiled tubing logging plug and formed to prevent a fluid flow through the through-hole of the coiled tubing logging plug, wherein the sealing body has an outer contour that at least partially is complementary in form with the through-hole of the coiled tubing logging plug.

Another object of the invention is to provide a method to reduce costs for situations in which the coiled tubing logging plug cannot be removed from the fluid tubing.

The invention is solved by a method for downhole sealing of a coiled tubing logging plug comprising the step of inserting an inventive sealing tool into a through-hole of the coiled tubing logging plug.

According to the invention it was recognized that the provision of the inventive sealing tool prevents the need to exchange the bypass-system. In particular, it has been recognized that by provision of the sealing tool the fluid tubing of the bypass-system can be sealed so that the fluid extraction operation can be performed by the electrical submersible pump without the risk that a self-circulation situation will occur. In particular, it was recognized that the coiled tubing logging plug cannot be removed from the fluid tubing as a pin could not be sheared and/or the bottom crossover could not shoulder the bottom edge of the collet lock on the coiled tubing plug and in turn unlock the locking mechanism so that the plug cannot be retrieved or removed and remains in its position. Thus, it is possible to insert the sealing tool into the coiled tubing logging plug in order to seal the fluid tubing. In the end high costs can be saved by avoiding the exchange of the bypass-system due to insertion of the sealing tool into the through-hole of the coiled tubing logging plug.

According to the invention the sealing body is configured to be removably insertable into a through-hole of the coiled tubing logging plug. This means, the sealing body and the coiled tubing logging plug are separate components wherein the sealing body can be inserted into the coiled tubing logging plug if it is needed. Additionally, the sealing body can be removed from the coiled tubing logging plug if the operator wants to unseal the fluid tubing of the bypass-system in order to access a well bore below the fluid tubing into the lower completion.

The sealing body is formed such that it prevents a fluid flow through the through-hole of the coiled tubing logging plug. This means, no fluid can flow from the fluid tubing of the bypass-system through the coiled tubing logging plug arranged in the fluid tubing into e.g. a production tubing fluidically connected to the bypass-system. Thereto, at least a part of the outer contour of the sealing body is configured such that it has a complementary form with a part of the through hole of the coiled tubing logging plug. That means, the outer contour of said part of the sealing body is in contact with an inner part of the coiled tubing logging plug such that no fluid, in particular liquid, can pass through between said part of the sealing body and the part of the coiled tubing logging plug.

Downhole sealing means that the sealing tool is adapted that the coiled tubing plug can be sealed when it is arranged downhole in a fluid tubing of e.g. the bypass-system in which the electrical submersible pump is arranged. The fluid can be a gas or liquid. The liquid can be oil or water.

According to an embodiment of the invention the sealing body can be made from bulk or solid material. In particular, the sealing body can be made from bulk or solid material such that no fluid can flow through the sealing body. Thus, no fluid can flow along the axial direction of the sealing tool between an end of the sealing tool directed to the production tubing and another end offset to the producing tubing. In the end, an easy shaped and formed sealing tool can be provided in order to ensure the sealing function.

The sealing tool does not have any external ports or a meaning for hydraulics fluids movement to enter through the tool or interact with parts of the coiled tubing logging plug. The sealing tool does not have any fluid chambers to help release the collects from the engagement area of the coiled tubing logging plug. Additionally, the sealing tool does not allow annulus flow around it to pass through the coiled tubing plug due to the fact that it generates a seal in the upper sub of the coiled tubing plug. In addition, the sealing tool does not have any holes, ports or cavities so that no fluid, in particular liquid, can pass through the tool. This is not possible as the tool is from bulk or solid material. The sealing tool can be used to seal an upper end of the coiled tubing logging plug.

The sealing body can have at least partially a cylindrical shape. As mentioned above, the sealing body has an outer contour that at least partially is complementary in form with the through-hole of the coiled tubing logging plug. Thus, it is ensured that the sealing body can be inserted into the through hole of the coiled tubing logging plug and to seal the coiled tubing logging plug.

The sealing body can comprise a first sealing body portion and a second sealing body portion wherein the diameter of the first sealing body portion differs from the diameter of the second sealing body portion. The diameter of the first sealing body portion can be greater than the diameter of the second sealing body portion. The fist sealing body portion can have a diameter in the range of <NUM>,<NUM> to <NUM>,<NUM>. The second sealing body portion can have a diameter in the range of <NUM>,<NUM> to <NUM>,<NUM>.

The first sealing body portion and the second sealing body portion can be arranged adjacent to each other along the axis of the sealing tool. For sealing the coiled tubing logging plug the sealing tool passes through sections of the coiled tubing logging plug that have different inner diameters. The sealing tool enables to seal the coiled tubing logging plug at two sections of the coiled tubing logging plug having different inner diameter. This is possible as the outer contour of each of said two sealing body portions is complementary with the form of the respective part of the coiled tubing logging plug. The first sealing body portion can seal an upper part of the coiled tubing logging plug. The upper part can comprise an end of the coiled tubing logging plug. The second sealing body portion can seal another part of the coiled tubing logging plug that is arranged lower than the upper part of the coiled tubing logging plug. The other part of the coiled tubing logging plug can be arranged between the ends of the coiled tubing logging plug. "upper" and "lower" refer to gravity direction.

The sealing body can comprise a tapering end portion. The second sealing body portion can be arranged closer to the tapering end portion than the first sealing body portion. The tapering end portion can be arranged at the end of the sealing tool offset to the production tubing. The tapering end portion, in particular a cross section of the tapering end portion, can decrease in a direction directed away from the remaining part of the sealing body, in particular the second sealing body portion. That means the tapering end portion decreases in the direction away from the production tubing. The tapering end portion can have a rounded nose. In particular, the nose can be arranged at the tip of the tapering end portion.

The tapering end portion has the advantage that the sealing tool can easily be inserted into the through hole of the coiled tubing logging plug. Additionally, the tapering end portion has the advantage that it helps to push any debris or leftover from coiled tubing logging cuttings after cutting the coiled tubing logging which is explained below more in detail. The rounded nose also ensures that the coiled tubing logging plug is not damaged when the sealing tool is inserted into the through-hole of the coiled tubing logging plug.

The sealing body can comprises a fishing portion for fishing the sealing tool. As fishing it is understood the operation of removing the sealing tool form the coiled tubing logging plug. The fishing portion is the part of the sealing body which is coupled with a fishing tool during the fishing operation. The fishing portion can be arranged at another end of the sealing body. Thus, the fishing portion is arranged at the other end of the sealing body that is proximal to the production tube and/or is opposite to the tapering end portion.

The sealing tool can comprise at least one sealing element arranged on the sealing body. In particular, the sealing tool can comprises several sealing elements that are arranged on the sealing body and that are arranged adjacent to each other along an axial direction of the sealing body. The sealing element can be an O-ring and/or can extend in circumferential direction of the sealing body. In particular, the sealing element can be arranged in a groove of the sealing body. The first sealing body portion comprises at least one sealing element and/or the second sealing body portion comprises at least one sealing element.

The sealing tool can comprise four sealing elements. Two sealing elements can be arranged on the second sealing body portion and thus seal an upper sub of the coiled tubing logging plug, in particular can seal a flow tube of the upper sub of the coiled tubing logging plug. The remaining two sealing elements can be arranged at the first sealing body portion.

The sealing tool can be fixed within the coiled tubing logging plug by means of a form-fit or friction connection. The sealing body can comprise a fixing portion for fixing the sealing tool with the coiled tubing logging plug wherein the fixing portion has a higher roughness than the remaining portion of the sealing body. The fixing portion is configured such that the connection between the sealing tool and the coiled tubing logging plug does not release during normal operation due to e.g. pressure differences within the bypass-system. However, the connection between the sealing tool and the coiled tubing logging plug is released if a fishing tool is coupled with the fishing portion of the sealing tool and acts a releasing force on the sealing tool. By provision of the fixing portion the sealing tool can be connected with the coiled tubing logging plug in an easy way ensuring that the connection does not unintentionally release. The fixing portion can also seal the coiled tubing logging plug. In that case the seal is realized by a metal to metal connection between the fixing portion and an upper end of the coiled tubing logging plug.

After the sealing tool is inserted into through-hole of the coiled tubing logging plug the fishing portion is arranged outside the through-hole. This means, the fishing portion is not arranged inside the through-hole of the coiled tubing logging plug. Thus, a fishing tool can easily be connected with the fishing portion of the sealing tool.

According to an embodiment of the invention the sealing body can comprise a spacer portion for preventing that a sealing element gets into contact with a tubing wall during the movement of the sealing tool towards the coiled tubing logging plug. Thus, it can be prevented in an easy way that the sealing element or sealing elements is or are damaged when the sealing tool is moved towards the coiled tubing logging plug in order to insert the sealing tool into the coiled tubing logging plug. The spacer portion can be arranged between the at least one sealing element and the fishing portion of the sealing body. The tubing wall can be the wall of the production tubing.

The spacer portion can have a greater outer contour than the remaining part of the sealing body. In particular, the diameter of the spacer portion can be greater than the diameter of the remaining part of the sealing body. Thus, it can be secured in an easy way that the sealing element does not contact the tubing wall. The spacer portion can have a greater dimension than the through-hole of the coiled tubing logging plug. Thus, the spacer portion is not inserted into the through-hole of the coiled tubing logging plug but is arranged outside the through hole. That means, a part of the sealing tool is arranged inside the through hole of the coiled tubing logging plug whereas the spacer portion is arranged outside the coiled tubing logging plug. As the spacer portion is arranged outside the through-hole it can also be used for fishing the sealing tool for the case that the fishing portion is damaged and/or cannot be coupled with the fishing tool. The spacer portion does not come in contact with the coiled tubing logging plug when the sealing tool is inserted into the coiled tubing logging plug.

A particular advantageous sealing tool is achieved if a distance between the spacer portion and a seating part of the tapering end portion is between <NUM>% to <NUM>% of the complete length of the sealing body. By choosing said length it can be secured that the sealing element does not come in contact with the tubing wall. The length of the sealing tool is its extension in axial direction of the sealing tool. The seating part of the tapering end portion is the end of the tapering end portion that is directed to the remaining part of the sealing body and that comes in contact with the tubing wall during the movement of the sealing tool in e.g. the production tubing.

Of particular advantage is a well system comprising the coiled tubing logging plug and a sealing tool according to the invention. The sealing tool is arranged in the through-hole of the coiled tubing logging plug in order to prevent a fluid flow through the through-hole of the coiled tubing logging plug.

The well completion system comprises a bypass-system, wherein the coiled tubing logging plug is located at a seating element of a fluid tubing of the bypass-system. That means, the sealing tool is in direct contact with the coiled tubing logging plug and/or is not in direct contact with the fluid tubing. In particular, the sealing of the coiled tubing logging plug, in particular the sealing of the through hole, can merely be achieved by the sealing tool. The seating element can be a part of the fluid tubing that protrudes in a radial inner direction from the remaining part of the fluid tubing. The well system can be fluidically connected with the production tubing.

The bypass-system comprises a further fluid tubing. A pump of the well system, in particular an electrical submersible pump, can be arranged in the further fluid tubing and/or can be fluidically connected with the further fluid tubing. The further fluid tubing is arranged partially parallel to the fluid tubing. The two tubings are fluidically connected at an upper and lower end with each other.

An outer contour of a cross section of the sealing body is smaller than an outer contour of a cross section of the coiled tubing logging plug. In particular, an outer diameter of the sealing body is smaller than an outer diameter of the coiled tubing logging plug. Additionally, the outer diameter of the sealing body, in particular the first sealing body portion and the second sealing body portion, is smaller than an inner diameter of the fluid tubing. In other words, the sealing tool cannot seal the fluid tubing. The same applies if the sealing tool is used in the further tubing in which the electrical submersible pump is arranged. The sealing tool can be coaxially arranged with the coiled tubing logging plug after the sealing tool is arranged in the through hole of the coiled tubing logging plug.

In the following, the method for sealing the coiled tubing logging plug is described. After it is determined that the coiled tubing logging plug is stuck and cannot be removed from the bypass-system a tube passing through the coiled tubing logging plug can be cut. The tube passes completely through the coiled tubing logging plug. The coiled tubing logging plug is fixedly seated on a seating element of the fluid tubing.

As a result of the cutting step a part of the cut tube falls downward due to gravity force. The remaining part of the cut tube can be removed in the next step. Afterwards, the sealing tool is inserted into the producing tubing and moved towards the coiled tubing logging plug. The sealing tool is moved such that it enters the through-hole of the coiled tubing logging plug and seals it so that no fluid can flow through the coiled tubing logging plug. In particular, the sealing tool can be moved such into the coiled tubing logging plug so that the fixation portion is fixed with the coiled tubing logging plug. Then, the sealing tool cannot be moved anymore relative to the coiled tubing logging plug. After the coiled tubing logging plug is sealed the electrical submersible pump can be activated so that it pumps the fluid through the bypass systems towards the production tubing.

According to an example a tool running procedures can be done using coiled tubing or wireline assembly tacking into account the connection of the fishing portion. Once the fishing operations deemed unsuccessful then the sealing tool can be inserted in the coiled tubing plug to seal it allowing the well to flow via ESP. The sealing tool designed for specific oil producing wells with Y tool completion design (artificial lift completion) and meant to seal the coiled tubing plug or to seal the flow through coiled tubing plug and allow production through production tubing and ESP pump side.

In the figures, the subject-matter of the invention is schematically shown, wherein identical or similarly acting elements are usually provided with the same reference signs. Here shows:.

<FIG> shows a perspective view of the sealing tool <NUM> according to the invention and <FIG> shows a cross section of the sealing tool <NUM> inserted in a coiled tubing logging plug <NUM>, wherein only a part of the coiled tubing logging plug <NUM> is shown in <FIG>. The sealing tool <NUM> and the coiled tubing logging plug <NUM> are arranged coaxially to each other when the sealing tool <NUM> is inserted in the coiled tubing logging plug <NUM> as is shown in <FIG>.

The sealing tool <NUM> shown in <FIG> is used for downhole sealing of the coiled tubing logging plug <NUM> that is shown in <FIG>. The sealing tool <NUM> has a sealing body <NUM> that is configured to be removably inserted into a through-hole <NUM> of the coiled tubing logging plug <NUM>. Additionally, the sealing body is <NUM> is formed such to prevent a fluid flow through the through hole <NUM> of the coiled tubing logging plug <NUM>. In particular, it is prevented that fluid can flow through the coiled tubing logging plug <NUM> along the axial direction A of the sealing tool <NUM> when the sealing tool <NUM> is inserted into the coiled tubing logging plug <NUM>. The sealing body <NUM> has a fist sealing body portion 4a and a second sealing body portion 4b wherein the first sealing body portion 4a and the second sealing body portion 4b are arranged adjacent to each other along the axial direction of the sealing tool <NUM>. The first sealing body portion 4a has a greater diameter than the second sealing body portion 4b.

The sealing body <NUM> is formed from bulk or solid material preventing any fluid flow from the through hole <NUM> along the axial direction A when the sealing tool <NUM> is inserted in the coiled tubing logging plug <NUM>. Additionally, the sealing body <NUM> comprises four sealing elements <NUM> that extend in circumferential direction around the sealing body <NUM>. The sealing elements <NUM> are arranged in grooves of the sealing body <NUM>, respectively. The sealing elements <NUM> are arranged adjacent to each other in axial direction A. Two of the sealing elements <NUM> that are arranged on the second sealing body portion 4b are in contact with an upper sub of the coiled tubing logging plug <NUM>, in particular of a flow tube of the upper sub of the coiled tubing logging plug <NUM>. The remaining two sealing elements <NUM> that are arranged on the first body portion 4a are in contact with a metal portion of the coiled tubing logging plug <NUM>, in particular an upper end of the coiled tubing logging plug <NUM>. Thus, it is secured by the sealing elements <NUM> that no fluid can flow between the sealing tool <NUM> and the coiled tubing logging plug <NUM> when the sealing tool <NUM> is inserted in the coiled tubing logging plug <NUM>. As is evident from <FIG> the first sealing body portion 4a and the second sealing body portion 4b come in contact with different parts of the coiled tubing logging plug, in particular with the upper part of the coiled tubing logging plug. Said parts of the coiled tubing logging plug have different inner diameters.

The sealing body <NUM> comprises a tapering end portion <NUM> that is arranged at an end of the sealing tool <NUM>. The tapering end portion <NUM> comprises a rounded nose <NUM> and decreases in a direction away from the sealing elements <NUM>. The tapering end portion <NUM> comprises a seating part <NUM> at the end of the tapering end portion <NUM> that is connected with the remaining sealing body <NUM>, in particular with the second sealing body portion 4b.

The sealing body <NUM> comprises a fixing portion <NUM> that has a different roughness than the remaining part of the sealing body <NUM>. The fixing portion <NUM> is used for connecting the sealing tool <NUM> with the coiled tubing logging plug <NUM> as it is shown in <FIG>. In particular, the sealing tool <NUM> is connected with the upper sub of the coiled tubing logging plug <NUM>. The connection is made such that the sealing tool <NUM> cannot move relative to the coiled tubing logging plug <NUM>. The fixing portion <NUM> is arranged at an end of the first sealing body portion 4a that is distant to the second sealing body portion 4b.

The sealing tool <NUM> comprises a fishing portion <NUM> that is arranged at another end of the sealing tool <NUM>. In particular, the fishing portion <NUM> and the tapering end portion <NUM> are arranged at opposite ends of the sealing tool <NUM>. The fishing portion <NUM> is connected with a non-shown fishing tool if the connection between the sealing tool <NUM> and the coiled tubing logging plug <NUM> shall be released. The fishing portion <NUM> remains outside the coiled tubing logging plug <NUM> when the sealing tool <NUM> is inserted in the coiled tubing logging plug <NUM>.

The sealing body <NUM> comprises a spacer portion <NUM> that is arranged between the fishing portion <NUM> and the sealing element <NUM>. The spacer portion <NUM> has a greater diameter than the remaining part of the sealing body <NUM>. As can be seen in <FIG> the spacer portion <NUM> remains outside the through-hole <NUM> when the sealing body <NUM> is inserted into the through-hole <NUM> of the coiled tubing logging plug <NUM>. The distance between the spacer portion <NUM> and the seating part <NUM> is so large that it is secured that the sealing element <NUM> does not contact any tubing wall <NUM> when the sealing tool <NUM> is moved through the production tube <NUM>.

The sealing body <NUM> including the spacer portion <NUM>, the fishing portion <NUM>, the fixing portion <NUM> and the tapering end portion <NUM> is formed as one piece component. That means said portions cannot be removed from each other without destroying the sealing body <NUM>.

<FIG> shows the movement of the sealing tool <NUM> within a production tubing <NUM> towards the coiled tubing logging plug <NUM> shown in <FIG>. The sealing tool <NUM> is moved along an insertion direction I towards the non-shown coiled tubing plug <NUM>. A non-shown tool is provided that moves the sealing tool <NUM> towards the coiled tubing plug <NUM> within the production tubing <NUM>.

As is evident from <FIG> the spacer portion <NUM> and the seating part <NUM> are in contact with a tubing wall <NUM> of the production tubing <NUM>. The sealing tool <NUM> is designed such that the distance between the spacer portion <NUM> and the seating part <NUM> along the axial direction of the sealing tool <NUM> is so long that the sealing elements <NUM> do not come in contact with the tubing wall <NUM>.

In the following, the method for sealing the coiled tubing logging plug <NUM> by means of the sealing tool <NUM> is described. The method is described under usage of <FIG>.

<FIG> shows a part of a well system <NUM> in a state in which the coiled tubing logging plug <NUM> is stuck. This means that the connection between the coiled tubing logging plug <NUM> and a fluid tubing <NUM> cannot be released so that the coiled tubing logging plug <NUM> cannot be moved in removal direction R.

The coiled tubing logging plug <NUM> seats on a seating element <NUM> of the fluid tubing <NUM>. A tube <NUM> extends through the complete coiled tubing logging plug <NUM>, in particular through the through-hole <NUM> of the coiled tubing logging plug <NUM>. <FIG> shows only a part of the tube <NUM>.

After, it has been determined that the coiled tubing logging plug <NUM> is stuck, the tube <NUM> is cut. The tube <NUM> can be cut at a portion that is arranged above the coiled tubing logging plug <NUM>. <FIG> shows the cutting position <NUM> at which the tube <NUM> is cut.

One part of the cut tube <NUM> falls downwards due to gravitationally force. This part is shown in <FIG> whereas the other cut tube part has been removed by moving it along the removal direction R. Afterwards, the sealing tool <NUM> is inserted into the through-hole <NUM> of the coiled tubing logging plug <NUM> as it is shown in <FIG>. Thereto, the sealing tool <NUM> has been moved along the insertion direction I.

<FIG> shows a well system <NUM> with a bypass-system <NUM>, the sealing tool <NUM> and the coiled tubing logging plug <NUM>. The sealing tool <NUM> is arranged inside the coiled tubing logging plug <NUM>.

The bypass-system <NUM> comprises a Y-tool. The Y-tool comprises the fluid tubing <NUM> discussed above. Additionally, the bypass-system <NUM> comprises a further fluid tubing <NUM> that is arranged parallel to the fluid tubing <NUM>. A pump <NUM> is arranged in the further fluid tubing <NUM> wherein the pump <NUM> can be an electrical submersible pump. The bypass-system <NUM> is fluidically connected with the production tubing <NUM>.

Claim 1:
Sealing tool (<NUM>) for downhole sealing of a coiled tubing logging plug (<NUM>), wherein
the sealing tool (<NUM>) comprises a sealing body (<NUM>) that is configured to be removably insertable into a through-hole (<NUM>) of the coiled tubing logging plug (<NUM>) and formed to prevent a fluid flow through the through-hole (<NUM>) of the coiled tubing logging plug (<NUM>), wherein
the sealing body (<NUM>) has an outer contour that at least partially is complementary in form with the through-hole (<NUM>) of the coiled tubing logging plug (<NUM>), wherein
the sealing body (<NUM>) comprises a spacer portion (<NUM>) for preventing that a sealing element (<NUM>) gets into contact with a tubing wall (<NUM>) during the movement of the sealing tool (<NUM>) towards the coiled tubing logging plug (<NUM>), wherein the spacer portion (<NUM>) is configured such to have a greater diameter than the through-hole of the coiled tubing logging plug (<NUM>) wherein
the sealing body (<NUM>) comprises a first sealing body portion (4a) comprising at least one sealing element and a second sealing body portion (4b) comprising at least one sealing element, wherein the diameter of the first sealing body portion (4a) differs from the diameter of the second sealing body portion (4b).