Patent Application
20180094506
The present invention relates to a downhole completion system and to a downhole communication or transferring method in a downhole completion system according to the present invention.
Many cased wells are double-cased, which induces the challenges of operating components down the well by means of control lines etc. Examples of prior art systems are described in e.g. US 2014/266210. When inserting casings having control lines on the outside, the control lines may be damaged or become inoperative over the years. When having an inner production casing with electrical lines along the outer face as in US 2014/266210, these electrical lines may become damaged when run in and when the barriers have been set, the inner production casing can be very difficult to pull out if tests show that the electrical lines have become damaged. Even if the electrical lines are successfully pulled out of the well, the annular barriers need to be replaced with new electrical lines before running the inner production casing in again.
Furthermore, such control lines may be displaced and thus interfere with the function of the component which is to be operated. Therefore, in recent years the wells have been developed to be simpler since the double-cased wells and the highly instrumented completions have shown not to function properly over a long time span. Furthermore, when abandoning a well, the control lines have also shown to constitute a challenge, since when cement is poured down the well to seal it, leakages occur along the control lines, and therefore many attempts have been made to develop methods of cutting these lines before abandoning the well.
It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved downhole system which is easy to operate and easy to replace and abandon.
The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a downhole completion system comprising:
Due to the fact that the electrical conductors run on the outside of the outer production casing below the main barrier, the inner production casing may be easily replaced by pulling the inner production casing, or just the upper part of the inner production casing, out and inserting a new one or a new upper part. Furthermore, no electrical conductors interfere with any completion components, e.g. sliding sleeves, in the inner production casing. And furthermore, when retrieving the inner production casing, or just the upper part of the inner production casing, the well can easily be abandoned by plugging and cementing it, and hence no electrical conductors are cemented, and thus there is no risk that the well will leak along such electrical conductors.
The second inner inductive coupling may be wireless.
Moreover, the inner production casing may comprise a first inner annular barrier and a second inner annular barrier configured to provide zonal isolation of a first inner zone in the secondary annulus, the first inner annular barrier being arranged between the first inner inductive coupling and the second inner inductive coupling, and the second inner annular barrier being arranged below the second inner inductive coupling, so that the second inner inductive coupling is arranged in the first inner zone.
Also, the inner production casing may comprise a completion component arranged between the first inner annular barrier and the second inner annular barrier.
Further, the second inner inductive coupling may be connected with the completion component.
In addition, the completion component may be an actuator for moving a sleeve in order to cover or uncover at least one inner opening in the inner production casing.
Moreover, the outer production casing may comprise a first outer annular barrier and a second outer annular barrier to provide zonal isolation of a first outer zone in the primary annulus.
Also, the outer production casing may have at least one outer opening between the first outer annular barrier and the second outer annular barrier.
An acid-soluble plug may be arranged in the outer opening in the outer production casing.
Furthermore, the second electrical conductor may electrically connect the first outer inductive coupling and the second outer inductive coupling, the second electrical conductor extending through the first outer annular barrier.
Additionally, a third outer annular barrier may be arranged below the second outer annular barrier to provide a second outer zone, and a third outer inductive coupling may be arranged in the second outer zone and may be connected with the second outer inductive coupling by an electrical conductor.
Also, an intermediate outer inductive coupling may be arranged on the outer face of the outer production casing above the main barrier and positioned substantially in the same horizontal level as the first inner inductive coupling for wireless transfer of communication signals and/or power therebetween, and the intermediate outer inductive coupling may be connected with the first outer inductive coupling via the second electrical conductor.
Further, a production packer may be arranged between the inner production casing and the outer production casing.
Moreover, a third inner annular barrier may be arranged below the second inner annular barrier to provide a second inner zone opposite the second outer zone.
Also, a third inner inductive coupling may be arranged in the second inner zone, the third inner inductive coupling being wireless.
The third inner inductive coupling may be connected with a second completion component.
In addition, the third outer inductive coupling may wirelessly transfer communication signals and/or power to the third inner inductive coupling.
Further, the inner production casing may have an upper part separated from a lower part, the first inner inductive coupling may be arranged on the upper part, and the first inner annular barrier may be arranged on the lower part.
The completion component may be a sensor.
Additionally, the sensor may be a temperature sensor or a pressure sensor.
Moreover, the lower part may have a polished bore receptacle for receiving the upper part.
The upper part may have no annular barriers.
Furthermore, the first inner annular barrier may be the barrier closest to the top.
The annular barrier in the downhole completion system, as described above, may comprise:
Each end of the expandable metal sleeve may be connected with the tubular metal part by means of connection parts.
Further, the inner annular barrier may be a packer.
Also, the electrical conductor may extend through the connection part of the annular barrier.
Said connection part may have a connection element for connecting and sealing the electrical conductor to the connection part.
Moreover, the expansion opening may be fluidly connected with a valve system.
The valve system may have two positions, a first position allowing fluid communication from inside the tubular part to enter the space, and a second position in which the fluid communication between the space and the inside is shut off and fluid communication between the space and the annulus is opened.
The downhole completion system may further comprise a control unit arranged within the inner production casing for moving a completion component, such as a sleeve, to open, choke or close the opening,
wherein the control unit may comprise:
The control unit may comprise a first communication module for receiving control signals from surface.
Furthermore, the outer production casing and/or the inner production casing may be mounted from tubular sections where at least one tubular section opposite one inductive coupling is made from a non-magnetic material, such as a non-magnetic metal.
The present invention also relates to a downhole communication or transferring method in a downhole completion system as described above, the downhole communication or transferring method comprising:
The second inner inductive coupling may then transfer signals and/or power to the completion component which then performs an operation, such as sliding or rotating the sleeve or measuring the temperature, pressure and/or flow of fluid.
After having performed the operation, the completion component may then send a signal to the second inner inductive coupling which transfers the signal to the second outer inductive coupling and further through the electrical conductor to the first outer inductive coupling and further to the first inner inductive coupling through the electrical conductor to surface.
The present invention also relates to a downhole completion method for completion of a downhole completion system as described above, the downhole completion method comprising:
In the event that the outer openings in the outer production casing comprise acid-soluble plugs, e.g. made of aluminium, the inner openings may be uncovered and acid may flow down the inner production casing and out into the inner zones to dissolve the acid-soluble plugs.
The present invention also relates to a downhole abandoning method for abandoning the downhole system as described above, the downhole abandoning method comprising:
The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:
All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.
The inner production casing further comprises a first inner annular barrier 34, 34a and a second inner annular barrier 34, 34b configured to provide zonal isolation of a first inner zone 36a in the secondary annulus. The first inner annular barrier is arranged between the first inner inductive coupling and the second inner inductive coupling, and the second inner annular barrier is arranged below the second inner inductive coupling, so that the second inner inductive coupling is arranged in the first inner zone.
The inner production casing comprises a completion component 37 arranged between the first inner annular barrier and the second inner annular barrier and the completion component 37 receives communication signals and/or power from the second inner inductive coupling. In
The second electrical conductor 6 electrically connects the first outer inductive coupling 21 and the second outer inductive coupling 22, and the second electrical conductor extends through the first outer annular barrier 24, 24a to be connected with a second outer inductive coupling 22.
The outer production casing further comprises a third outer annular barrier 24, 24c arranged below the second outer annular barrier to provide a second outer zone between the second outer annular barrier and the third outer annular barrier. A third outer inductive coupling 23 is arranged in the second outer zone 26b and is connected with the second outer inductive coupling by the electrical conductor 6. The inner production casing further comprises a third inner annular barrier 34, 34c arranged below the second inner annular barrier to provide a second inner zone 36b opposite the second outer zone. A third inner inductive coupling 33 is arranged in the second inner zone, and the third inner inductive coupling is wireless and thus not connected to an electrical conductor or any one of the induction couplings. The third inner inductive coupling is connected with a second completion component 37b, which is also an actuator for moving a sleeve to cover or uncover an outer opening 28. The third outer inductive coupling wirelessly transfers communication signals and/or power to the third inner inductive coupling which provides communication signals and/or power to the second completion component 37b.
The inner production casing 30 has an upper part 30a separated from a lower part 30b, and the first inner inductive coupling is arranged on the upper part and the first inner annular barrier is arranged on the lower part. The lower part has a polished bore receptacle 39 for receiving the upper part. By having the inner production casing divided in at least two parts, the upper part 30a can be designed without any annular barriers and it can easily be pulled for replacing the electrical conductor if the conductor shows to be deteriorated during the running in the inner production casing or later on. The lower part having annular barriers, i.e. the first inner annular barrier 34, 34a and the second inner annular barrier 34, 34b, does not have any electrical conductors and it is therefore not in the risk of having to be pulled due to conductor failure.
In
In
As shown in
The inner annular barrier may be a conventional packer and not an annular barrier shown in
The electrical conductor 6 extends through a connection part 59 of the annular barrier as shown in
The downhole system communicates and transfers communication signals and/or power by sending a signal and/or power from the top to the first inner inductive completion through the first electrical conductor, then wirelessly transferring the signal and/or power from the first inner inductive coupling to the first outer inductive coupling, and further sending the signal and/or power from the first outer inductive coupling to the second outer inductive coupling through a second electrical conductor, and then wirelessly transferring the signal and/or power from the second outer inductive coupling to the second inner inductive coupling.
The second inner inductive coupling then transfers signals and/or power to the completion component which then performs an operation, such as sliding or rotating the sleeve or measuring the temperature, pressure and/or flow of fluid.
After having performed the operation, the completion component may then send a signal to the second inner inductive coupling which transfers the signal to the second outer inductive coupling and further through the electrical conductor to the first outer inductive coupling and further to the first inner inductive coupling through the electrical conductor to surface.
The downhole system is completed by first drilling the borehole, then inserting the intermediate casing and cementing the intermediate casing to the wall of the borehole. Subsequently, a second part of the borehole is drilled and the outer production casing is inserted/run into the intermediate casing and the production casing extends further into the borehole than the intermediate casing. The main barrier is then expanded between the intermediate casing and the outer production casing, and subsequently the outer annular barriers are expanded to provide outer zones therebetween. Then the inner production casing is inserted into the outer production casing and the inner annular barriers are expanded to provide inner zones between the outer production casing and the inner production casing. In the event that the outer openings in the outer production casing comprise acid-soluble plugs, e.g. made of aluminium, the inner openings are uncovered and acid flows down the inner production casing and out into the inner zones to dissolve the acid-soluble plugs.
In the event that the well needs to be abandoned, the inner production casing is retrieved, and a plug is inserted into the outer production casing, and part of the well is then filled with cement on top of the plug and on top of the main barrier. Due to the fact that the inner production casing is retrieved and the electrical conductors run on the outside of the outer production casing below the main barrier, no electrical conductors are cemented, and thus there is no risk that the well will leak along such electrical conductors. The inner production casing may also be easily replaced by pulling the inner production casing, or just pulling the upper part of the inner production casing out and inserting a new one or a new upper part.
In
The control unit may thus comprise a communication module for receiving the signals and sending signals to surface through the inner and outer inductive couplings and the conductors.
In
Data from e.g. a sensor measuring pressure may be sent comprising only the differences in pressure from the most recent measurement and not the actual measurement. Actual measurements may also be sent, and in a period between sending two actual measurements, data reflecting only the difference in e.g. pressure from the most recently measured pressure may be sent several times during the period. The period may be varied when required.
Furthermore, in
The outer production casing and/or the inner production casing may be mounted from tubular sections where at least one tubular section opposite one of the inductive couplings is made from a non-magnetic material, such as a non-magnetic metal.
By fluid or well fluid is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By gas is meant any kind of gas composition present in a well, completion, or open hole, and by oil is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil, and water fluids may thus all comprise other elements or substances than gas, oil, and/or water, respectively.
By a casing is meant any kind of pipe, tubing, tubular, liner, string etc. used downhole in relation to oil or natural gas production.
Although the invention has been described in the above in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16191998.0 | Sep 2016 | EP | regional |
| 16193459.1 | Oct 2016 | EP | regional |
