BOREHOLE SHUT-IN SYSTEM WITH PRESSURE INTERROGATION FOR NON-PENETRATED BOREHOLE BARRIERS

Abstract

A borehole shut-in system with pressure interrogation for non-penetrated borehole barriers includes a first non-penetrated borehole barrier; a second non-penetrated borehole barrier in spaced relationship with the first non-penetrated borehole barrier. One or more sensors disposed downhole of one or more of the first and second borehole barriers; and a conductor disposed between the first and second borehole barriers and laminated into mandrels of the first and second barriers. The conductor in operable communication with the one or more sensors, the conductor configured to interrogate each of the one or more sensors and communicate data therefrom to a connector. A method of shutting in a borehole.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 62/013,222 filed Jun. 17, 2014 the entire disclosure of which is incorporated herein by reference.

BACKGROUND

In the hydrocarbon exploration and recovery industry, there can be a need to remove borehole equipment such as a tree or blow out preventer, etc. In such instances it is often required to install non-penetrated barriers in series per local regulations. Generally the barriers are placed in the vicinity of an uphole extent of a lower completion. It is important that the barriers be non-penetrated since penetrations represent potential leak paths through the barriers. Barriers must also be tested to ensure pressure integrity, which both assures control and complies with regulations. The issue comes from the fact that without penetrations, information about the borehole beyond the barrier has historically not been available. For a first barrier, this is problematic relative to a cement plug generally employed before the bridge plugs and for a second barrier it is because of the first barrier.

More specifically, before the first barrier is deployed in place, a cement plug is usually installed downhole of where the first barrier is to be placed. This means that when the first barrier is pressure tested by pressuring up on the borehole and watching for leakdown, it is not clear whether the seal is created by the barrier or by the cement plug. This is problematic as it is important to know if the barriers themselves are functioning properly. Another difficulty presents itself when a second barrier is added to the first. Pressuring up on the borehole after setting of the second barrier only provides information about the pair of barriers and the cement plug while it does not provide information to the operator about which among them is holding the pressure applied. It could be the second barrier if it is working correctly but it could just as easily be the first barrier or the cement plug that is holding the pressure. In such condition, it is possible that only one of the barriers is actually functioning or that neither barrier is functioning and that the cement plug is holding the pressure. There is in the art however no way to verify what is holding pressure. While applying pressure is the presently accepted method, the art is always receptive to better configurations and methodologies that provide more accurate and/or reliable information about the downhole environment.

BRIEF DESCRIPTION

A borehole shut-in system with pressure interrogation for non-penetrated borehole barriers includes a first non-penetrated borehole barrier; a second non-penetrated borehole barrier in spaced relationship with the first non-penetrated borehole barrier; one or more sensors disposed downhole of one or more of the first and second borehole barriers; and a conductor disposed between the first and second borehole barriers and laminated into mandrels of the first and second barriers, the conductor in operable communication with the one or more sensors, the conductor configured to interrogate each of the one or more sensors and communicate data therefrom to a connector.

A method of shutting in a borehole includes setting a first non-penetrated barrier at a selected location within the borehole; setting a second non-penetrated barrier at a second selected location within the borehole spaced from the first non-penetrated barrier; positioning one or more sensors downhole of one or more of the first and second barriers; and monitoring a parameter with one or more of the one or more sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE is a schematic representation of a portion of a borehole system where two barriers and a cement plug are positioned.

DETAILED DESCRIPTION

Referring to the FIGURE, a schematic illustration of a portion of a borehole system 10 is presented. A cement plug 12 is shown downhole of two barriers 14 and 16. These may be any suitable non-penetrated barriers and in one embodiment comprise one or more composite bridge plugs. Each barrier 14 and 16 is required to be a non-penetrated type barrier due to regulations in many jurisdictions before removal of borehole equipment such as a tree or a blowout preventer, for example. Although other barriers may be used as noted, those illustrated are bridge plugs commercially available from Baker Hughes Incorporated, Houston Tex.

A mandrel 18 is disposed between the two barriers thereby spacing them from one another by a selected distance. The distance is determined for the specific application, may be any distance that is convenient for a particular borehole system, and therefore disclosure of a range of distance is not germane to the present disclosure. The mandrel is associated with a conductor 20, such as, for example, a copper wire. The conductor 20 may be laminated into mandrel 18 as it extends between the two barriers in an embodiment or it may simply be run alongside the mandrel 18 as no leak path is created in this location.

The Conductor 20 must also pass through each barrier's mandrel, and must do so without the formation of a leak path. This is accomplished by laminating the conductor 20 into the composite along with the glass and the epoxy with which the composite is formed during construction of the bridge plugs or other types of barriers. Because of the incorporation in the laminate there can be no leak path created by the conductor through the barriers 14 and 16.

The conductor 20 is communicatively connected to sensors 22 and 24, which in one embodiment are pressure sensors. The sensors as illustrated are each downhole of a barrier or at least in operable communication with the target property as it exists in a volume defined at least in part by the relevant barrier. More specifically, sensor 22 is located downhole of barrier 14 and between barrier 14 and the cement plug 12; and sensor 24 is positioned downhole of barrier 16, between barrier 14 and barrier 16. The positions of the sensors allow for monitoring of properties to which the sensors are sensitive between structures that are intended to prevent migration of such properties. For example, if pressure is the property, each of the barriers 14 and 16 and the cement plug 12 itself are intended to prevent pressure communication across those barriers and the plug. Accordingly, if the barriers/plug are functioning appropriately there should be no change in pressure at the sensors. Each sensor is connected to the conductor 20, which in turn is connected to a connector 26. Connector 26 may be configured to support a data sub that is configured to record data from the sensors and download periodically to wireline or the like or the connector may be configured to connect to a permanent data line extending to a remote location, such as the surface. It is to be understood that any signal conveying configuration is acceptable and contemplated for connector 26 including electrical, optical, inductive, etc. With the system as disclosed herein, an operator can be appropriately, reliably and timely informed as to any changes in the barrier system. Further, the information can be trended over time thereby providing advance warning of any developing leak.

Regarding installation of the system, the barriers 14 and 16 can be configured and set as individual units, or as a single unit with two bridge plugs (or other barriers) thereon. From an illustration standpoint, the differing embodiments will look the same. If the units are run separately, there will be a wet connector positioned between the two barriers most likely at the uphole end of the barrier 14 and the downhole end of mandrel 18 but other locations are possible and contemplated. Wet connects are known to the art and easily understood by one of ordinary skill in the art. If the barriers are run separately, the first barrier 14 will normally be pressure tested before the second barrier 16 is deployed (set or run) If the barriers are run together as a single unit, a wet connector will not be needed as the conductor 20 will be connected at surface before running In such a system, it may be that the two barriers will be set simultaneously or may be that they are set seriatim, as desired. If set seriatim with barrier 14 set first, there remains the possibility to pressure test barrier 14 independently, if desired. It is noted however that in systems using the sensors 22 and 24 as taught herein, specific pressure testing is not necessary because monitoring of change in pressure after setting will provide sufficient information.

Also disclosed is a method of shutting in a wellbore using the system described above the method including: setting a barrier 14 and a barrier 16, positioning sensors in communication with volumes downhole of respective barriers and monitoring a parameter such as pressure with the sensors. The method further includes downloading information from the sensors to a remote location by periodic download or continuous communication.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Claims

1. A borehole shut-in system with pressure interrogation for non-penetrated borehole barriers comprising:

a first non-penetrated borehole barrier;

a second non-penetrated borehole barrier in spaced relationship with the first non-penetrated borehole barrier;

one or more sensors disposed downhole of one or more of the first and second borehole barriers; and

a conductor disposed between the first and second borehole barriers and laminated into mandrels of the first and second barriers, the conductor in operable communication with the one or more sensors, the conductor configured to interrogate each of the one or more sensors and communicate data therefrom to a connector.

2. The system as claimed in claim 1 wherein one or more sensors are pressure sensors.

3. The system as claimed in claim 1 wherein the conductor is a copper wire.

4. The system as claimed in claim 1 wherein the one or more sensors are positioned downhole of each barrier.

5. The system as claimed in claim 1 wherein the conductor is alongside a mandrel between the first and second borehole barriers.

6. The system as claimed in claim 1 wherein the conductor is laminated to a mandrel between the first and second borehole barriers.

7. The system as claimed in claim 1 wherein one of the first and second borehole barriers is a composite bridge plug.

8. The system as claimed in claim 1 wherein one or more sensors are positioned uphole of a cement plug and between the cement plug and the first borehole barrier.

9. The system as claimed in claim 8 wherein one or more sensors are positioned between the first borehole barrier and the second borehole barrier.

10. The system as claimed in claim 1 further comprising a connector operably attached to the conductor.

11. The system as claimed in claim 1 further comprising a wet connect in operable communication with the conductor between the first and second borehole barriers.

12. A method of shutting in a borehole comprising:

setting a first non-penetrated barrier at a selected location within the borehole;

setting a second non-penetrated barrier at a second selected location within the borehole spaced from the first non-penetrated barrier;

positioning one or more sensors downhole of one or more of the first and second barriers; and

monitoring a parameter with one or more of the one or more sensors.

13. The method as claimed in claim 12 further comprising communicating the monitored parameter from the one or more sensors through a conductor laminated through the mandrels of one or more of the first and second barriers.

14. The method as claimed in claim 12 further comprising downloading data regarding the monitored parameter.

15. The method as claimed in claim 12 further comprising recording data from the one or more sensors on a data sub.

16. The method as claimed in claim 12 wherein the setting of the first barrier and the second barrier occurs simultaneously.

17. The method as claimed in claim 14 wherein the downloading data includes connecting a wireline to a connector that is in turn connected to the one or more sensors.