System and method for deploying and using at least one control module for in-riser and open water operations

A technique facilitates control of subsea equipment by providing a modular electro-hydraulic control system which can be used with various types of subsea equipment. The modular system is constructed to accommodate high axial loading while also withstanding high bending forces. Additionally, the components of the modular system are constructed and arranged to enable the modular system to fit through a rotary table of a rig. Depending on the parameters of a given application, the modular control system may be utilized for open water operations and in-riser operations.

BACKGROUND

In a variety of subsea applications, many types of equipment may be deployed down through a marine riser and/or through the open water to a subsea well. The equipment is deployed to the subsea well, and each distinct system or tool has its own specific control system for controlling the various tool functions at the subsea location. For example, subsea test trees, tubing hangar running tools, and/or tree running tools may be deployed to the subsea well with their own specific control systems. Because each type of tool or equipment is coupled with its own dedicated control system, the change-over time between completing one operation and beginning another can be substantial. Additionally, the size of many of the control systems dictates that rig-up operations be performed in the moon pool area of a drilling rig rather than the rig floor which can create additional time requirements and complexities.

SUMMARY

In general, the present disclosure is related to a system and methodology which provide a modular electro-hydraulic control system which can be used with various types of subsea equipment. The modular system is constructed to accommodate high axial loading while also withstanding high bending forces. Additionally, the components of the modular system are constructed and arranged to enable the modular system to fit through a rotary table of a drilling rig. Depending on the parameters of a given application, the modular control system may be utilized for open water operations and in-riser operations.

DETAILED DESCRIPTION

The disclosure herein generally relates to a system and methodology for facilitating control over various types of subsea equipment, e.g. equipment deployed on drill pipe or other suitable conveyances. The system and methodology utilize a modular electro-hydraulic control system which can be readily assembled and used with various types of subsea equipment. The configuration of the modular system accommodates high axial loading while also withstanding high bending forces. As described in greater detail below, the modular electro-hydraulic control system utilizes at least one control module which is constructed to fit through a rotary table of a drilling rig, thus simplifying deployment of the subsea equipment. Depending on the parameters of a given application, the modular control system may be utilized for open water operations and in-riser operations.

According to a specific embodiment, the modular control system is constructed for deployment on drill pipe in an open water environment or through a marine riser. The construction and modularity of the system enables control of several different types of equipment, e.g. a subsea test tree (SSTT), a tubing hanger running tool (THRT) and/or a tree running tool (TRT), instead of using specific, dedicated control systems for each type of equipment. The modular control system may be deployed through a rig's rotary table, thus reducing change-over time between completing one subsea operation and beginning another. Because the components of the modular control system may be deployed through the rotary table, various additional rig-up operations can be moved to the rig floor rather than being performed in a moon pool area of the rig, thus further reducing time of assembly. The use of one control system rather than several different control systems also saves costs otherwise associated with the purchase or rental of the additional control equipment.

The modular control system may be constructed to utilize a variety of components depending on the parameters of a given operation. For example, the modular control system may comprise an inner mandrel which carries well fluids therethrough and also attaches to a suitable conveyance, e.g. drill pipe. The inner mandrel may be changed depending on the pressures and tensions involved in a given well application. By way of example, the inner mandrel may have flange connections at its ends to facilitate connection with other modules. Devices such as accumulators, regulators, and hydraulic manifolds may be selectively mounted to the outside of the inner mandrel to facilitate control over the subsea equipment, e.g. to supply hydraulic power and/or chemical injection for the SSTT and THRT. An instrumentation module also may be mounted on the inner mandrel to, for example, measure pressure on the hydraulic output lines. The entire assembly may be constructed to fit through a rotary table and to move along the inside of a marine riser for in-riser operations.

A second module, e.g. an open water control module, may be coupled into the modular control system. By way of example, the second module may comprise additional accumulators, manifolds, and other devices mounted on a second internal mandrel. The second module also may utilize flange connections or other suitable connections for coupling with other components of the overall modular control system. The second control module also is constructed to fit through the rotary table and may be utilized in a variety of operations, including open water tree running tool (TRT) operations.

In an operational example, the modular control system can be used during well construction after a subsea well has been cased and perforated. At this stage, a completion can be run downhole into the subsea wellbore with subsea equipment, e.g. a tubing hanger, THRT, and SSTT. The modular control system is used to maintain well control through the subsea test tree and to conduct well test operations. The well string and riser can then be recovered to the rig, and the TRT can be connected to the well test string along with a Christmas tree, e.g. a horizontal Christmas tree, for subsequent deployment to the subsea well.

In many applications, these types of equipment, e.g. horizontal Christmas trees, are too large to go to the rotary table and are rigged up in the pool area of the rig. While this equipment is rigged up in the moon pool area, the modular control system can be rigged up above the rotary table and the second control module and/or other control modules may be attached as desired for a given application. When the Christmas tree and TRT are ready to be deployed, the modular control system is connected to the TRT and run down through the rotary table so that the entire system may be deployed through open water until the Christmas tree is set at the desired subsea well location. Subsequently, additional flow back operations and/or intervention operations can be connected using the same modular control system via, for example, the added second control module.

Referring generally toFIG. 1, an example of a modular electro-hydraulic control system20is illustrated. The modular control system20may be attached into a variety of well strings for use in controlling different types of subsea equipment. In the embodiment illustrated, the modular control system20comprises a subsea control module22which may have a variety of components selected according to the parameters of a desired operation. For example, the subsea control module22may have an internal mandrel24to which various components are mounted.

In the embodiment illustrated, a plurality of accumulators26is mounted about the internal mandrel24. Additionally, a valve section27comprising valves/regulators28may be mounted about the mandrel24and may be operated in cooperation with hydraulic manifolds30to control the supply of hydraulic actuation fluid and/or chemical injection fluid to desired subsea equipment tools, e.g. an SSTT or THRT. By way of example, the valves28may be solenoid operated valves. In some applications, an instrumentation module32also may be mounted to mandrel24. By way of example, the instrumentation module32may include a gauge package34.

The illustrated embodiment of modular control system20also comprises an additional control module36, e.g. an open water control module. The control module36is easily coupled into the overall control system20by suitable connectors, e.g. flange connectors38. In some applications, at least one of the flange connectors38may comprise a crossover flange for coupling a crossover member40into the overall modular control system20. Similarly, other components may be coupled into the control system20by flange connectors38or by other suitable connectors. For example, a supplemental control module or modules42may be added to the control system20.

Depending on the application, the control modules22and/or36may be used to control a variety of electrical and/or hydraulic inputs. In some applications, an umbilical44is coupled with the modular control system20and may comprise hydraulic control lines46and/or electrical control lines48. By way of example, the hydraulic control lines46may be used to provide hydraulic control signals to appropriate subsea equipment components, to deliver chemical treatments, and/or to provide other desired hydraulic inputs. In some applications, the entire grouping of hydraulic control lines46and/or electrical control lines48are encased in the single umbilical34. However, certain applications may utilize a second umbilical50having similar hydraulic, electrical, and/or other control lines. For example, some applications may utilize the first umbilical44to encase the hydraulic supply lines46while the second umbilical50encases the electrical control lines48. Pressures in the hydraulic control lines46may be monitored by the sensors of gauge package34or other appropriate sensors in communication with the hydraulic control lines. Sections of umbilicals44,50(or sections of the control lines) also may be routed along the modular control system20from the control modules22,36to desired controlled tools of the subsea equipment.

With additional reference toFIG. 2, an example of the control module36is illustrated. By way of example, the control module36may be used as an open water control module. In this embodiment, the control module36comprises an inner mandrel52which may have a hollow interior for carrying well fluids and also may be coupled with a suitable conveyance, e.g. drill pipe. As with inner mandrel24, mandrel52can be changed depending on the pressure and tension parameters encountered in a given well application. The inner mandrel24may comprise or may be coupled with suitable end connectors, such as flange connectors38to facilitate connection to other modules.

Additionally, the control module36, e.g. open water control module, may comprise various other components selectively mountable to inner mandrel52. For example, a plurality of accumulators54may be mounted about the internal mandrel52. Hydraulic manifolds56also may be mounted about internal mandrel52and may work in cooperation with a plurality of valves/regulators58to control the supply of hydraulic actuation fluid and/or other hydraulic fluid to desired subsea equipment, e.g. an SSTT, THRT, TRT, and/or other controlled tools. By way of example, the valves58may be solenoid operated valves. In some applications, an instrumentation module60comprising desired sensors62, e.g. pressure sensors, also may be mounted to internal mandrel52. By way of example, sensors62may be used to monitor pressure in hydraulic lines46and/or to monitor other pressures or parameters related to operation of the subsea equipment.

Both the inner mandrel24and the inner mandrel52are constructed to accommodate high axial loading while also withstanding high bending forces. This enables use of subsea control module22and/or additional control module36to be used in both in-riser and open water operations. Additionally, the modularity of the system enables easy replacement of one of the control modules22,36or even replacement of the desired internal mandrel24,52so as to accommodate changing pressure and/or tensile loading parameters of a given subsea operation.

The size of the subsea control module22and the additional open water control module36also facilitate timely rig-up of components and interchanging of components because the control modules22,36are able to easily pass through a rotary table64of a rig66, as illustrated inFIG. 3. In this example, the overall modular control system20is illustrated as coupled with a top drive68via a coupling mechanism70. The top drive68may be used to move the modular control system20into position over rotary table64for coupling into an overall subsea well string72which may comprise drill pipe74or other types of conveyances. In the example illustrated, the modular control system20is assembled into the well string72on rig66above the rotary table64.

However, other components of the overall well string72may be assembled in a pool area76below the rotary table64. For example, a running tool78, e.g. a tree running tool, may be coupled with subsea equipment80and a stiff transition joint82extending below rotary table64. In the specific example illustrated, the running tool78is coupled with a horizontal Christmas tree84. Depending on the application, additional components may be joined above and/or below rotary table64. In the example illustrated, a stab plate86is located above rotary table64and a second stab plate88is disposed below rotary table64. Additionally, another coupling, e.g. flange joint38, may be positioned to join the components assembled above the rotary table64with those assembled below, as illustrated.

In an operational example, the subsea control module22and the additional control module36, e.g. open water control module, of overall modular control system20may be used to control running tool78during an open water configuration, as illustrated inFIG. 4. In the specific example, the control module36may be used in cooperation with subsea control module22to control running tool78. Running tool78may be in the form of a tree running tool used to deploy horizontal Christmas tree84to a desired subsea location90above a well92.

However, the open water control module36may be used in a variety of other open water applications to control other devices, such as a subsea test tree or a tubing hanger running tool. The control module36(and subsea control module22) is constructed with the appropriate components, e.g. manifold56, valves58, instrument module60, sensors62, to enable use of the control module36with a variety of different types of subsea equipment, e.g. subsea tools.

In another operational example, the modular control system20may be used for an in-riser application, as illustrated inFIG. 5. By way of example, the modular control system20may be used to control a subsea test tree94deployed into a riser96for use at a subsea installation98. In the example illustrated, the subsea test tree94is received into an interior100of the subsea installation98. The subsea installation98may comprise various components, such as flow line fixtures102disposed above horizontal Christmas tree84. Additionally, the subsea installation may comprise a variety of rams104, e.g. pipe rams, shear rams, and/or annular rams, as well as other features106selected according to the parameters of a given application.

In some applications, the riser96may not have a large enough interior diameter to accommodate the control module36, and/or the subsea equipment, e.g subsea test tree94, may not utilize the additional control capabilities provided by control module36. The modularity of the overall control system20enables easy removal of control module36and/or later addition of control module36. For example, control module36may be added for a subsequent subsea operation, e.g. open water running of a tree running tool78with a Christmas tree, and control of another tool, e.g. control of the TRT78. Similarly, additional modules42may be easily added or removed according to the control capabilities desired for a given subsea application.

The modular control system20is highly adaptable and may be used in a wide variety of subsea operations to control many types of subsea equipment. For example, the modular control system20may be in the form of a modular electro-hydraulic control system, as described above, for use with a subsea wellhead or subsea test tree. The modular control system20is able to accommodate high axial loading and also high bending forces by selecting the appropriate inner mandrel24and inner mandrel52of control modules22and36, respectively. The ability to select appropriate mandrels to handle high axial and bending loads and the modularity of the overall system enables easy adaptation of the modular control system20for use in both open water operations and in-riser operations.

The subsea control module22and the control module36are able to fit through the rotary table64of rig66, e.g. a drilling rig, and also may be constructed with standard configurations for in-riser operations. However, the control module36may easily be removed from the overall modular control system20if the inner diameter of the riser is too small or if the control features of module36are not used for a given operation. Each control module22,36may constructed with the appropriate accumulators, valves, e.g. solenoid operated valves and/or directional control valves, sensors, and/or other components to accommodate the parameters of a given subsea operation. In some applications, the sensors, e.g gauge package34of control module22and/or sensor62of control module36, may be used to monitor pressure in hydraulic control lines46.

In some applications, the modular control system20may comprise both subsea components and surface components, e.g. a surface control system108as illustrated inFIGS. 4 and 5. The surface control system108may be used to control the delivery of signals, e.g. hydraulic and/or electric signals, down to control modules22,36through umbilicals44,50. The hydraulic control lines46and/or electrical control lines48may be encased in a single umbilical, e.g. umbilical44, or a plurality of umbilicals, e.g. umbilicals44and50. In some applications, each umbilical44,50may contain different types of control lines, e.g. hydraulic control lines46in umbilical44and electrical control lines48in umbilical50. The control lines46,48also may be routed between components of the modular control system20and the controlled subsea equipment/tools.

The modularity of the overall control system20reduces the time involved in assembling the well string72and also provides great flexibility with respect to which components and systems are added for a given subsea application. The construction also enables assembling of some components above rotary table64while other components are assembled in the pool area76below the rotary table64. For example, subsea control module22, open water control module36, and their cooperating control system components may be assembled above the rotary table64. However, the subsea Christmas tree84, lower riser96, associated riser package components, and tree running tool78may be assembled and connected below the rotary table64.

The stress joint82may be located so as to protrude through the rotary table64to facilitate coupling of the modular control system20with the controlled subsea equipment, e.g. tree running tool78. The umbilical44or umbilicals44,50may be deployed alongside. It should be noted that many other types of controlled subsea equipment, as described above, may be coupled with the modular control system20via umbilicals or other types of control lines.

The system and methodologies described herein may be employed in a wide variety of subsea well operations and other subsea operations. The overall structure of the well string72, e.g. drill string, may vary substantially according to the parameters of a given subsea operation. Similarly, the components of the modular control system20also may be selected according to the specifics of the subsea operation. The modularity of system20enables the overall control system to be rapidly assembled and/or changed to accommodate different types of devices and systems to be controlled during the subsea operation. Similarly, the components used to construct the subsea control module22and/or control module36may be selected and/or changed to facilitate the control parameters of the corresponding subsea operation.

Although a few embodiments of the system and methodology have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.