Patent Application
20130020097
Embodiments described relate to tools and techniques for wireless actuation of a downhole tool. In particular, equipment and techniques for fluid-flow communication and actuation in a substantially “open-hole” or non-pressurizable environment relative to the tool's downhole pressure environment are described. Packers, hydrostatic set modules, and zonal isolation are detailed in this regard. However, communication to and/or actuation of a variety of alternative tools and downhole circumstances may be applicable.
Exploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming, risky and ultimately very expensive endeavors. As a result, over the years, a significant amount of added emphasis has been placed on overall well architecture, monitoring and follow on interventional maintenance. Indeed, perhaps even more emphasis has been directed at minimizing costs associated with applications in furtherance of well construction, monitoring and maintenance. All in all, careful attention to the cost effective and reliable execution of such applications may help minimize risks, maximize production and extend well life. Thus, a substantial return on the investment in the completed well may be better ensured.
Completions assemblies, which govern production through the well, are generally outfitted with fairly standard equipment in line with the objectives of maximizing cost effectiveness and overall production. For example, the well may be tens of thousands of feet deep and traverse a variety of different formation layers. Therefore, the completions assembly may be outfitted with a host of different sliding sleeves, packers and other location specific equipment for aiding and directing production. In a more specific example, packers may be intermittently disposed about production tubing which runs through the well so as to isolate various well regions or zones from one another. Thus, production may be extracted from certain zones through the production tubing, but not others. Similarly, production tubing that terminates adjacent a production region is generally anchored or immobilized in place thereat by a mechanical packer, irrespective of any zonal isolation.
Setting of packers and other actuations may be directed over a power data cable running from surface to a downhole setting tool. However, in circumstances where such a cable serves no significant other useful purpose, efforts are generally undertaken to avoid cable use in directing one-time actuations such as packer setting. Alternatively, wireless pressure pulse communication between surface and a downhole setting tool may be employed. In this manner, use of dedicated, non-ergonomic cabling may be avoided. As a practical matter, this may be a significant benefit given the expense, risks and nature of installing and working around several thousand feet of cumbersome cabling.
Unfortunately, pressure pulse communication is not always available or effective. This is because in order for such communications to take place, a substantially closed completions assembly is required. That is, in a pressure sense, in order to effectively propagate a pressure pulse signal from surface equipment, throughout the assembly, and toward an actuator tool, a substantially closed fluidic system is required. However, in many circumstances, such a system is not available or effective. For example, the completions assembly may be completely open to the well at its terminal end or perhaps outfitted with a slotted liner. In fact, even the presence of a significant number of perforations running along the assembly as it traverses different formation layers may provide enough ‘openness’ to the system to render pressure pulse communication ineffective because such pressure pulses are dissipated, attenuated or absorbed by those opened layers' permeable formations and natural pressure sources.
Most completions assemblies don't require long-term power supply or dedicated monitoring. Therefore, as a matter of cost and ergonomics, cabling as described above is generally avoided. However, with a dedicated power data cable unavailable, options for actuating a downhole tool are limited. This is particularly true where wireless pressure pulse communication is unavailable due to openness of the completions assembly in circumstances such as those described above.
Alternatively, other wireless communications methods, based on either electromagnetic or acoustic techniques, may also be unavailable or ineffective for communications. For example, in deep water or sub-sea well completions applications the communications media may absorb or dissipate the electromagnetic or acoustic signal's power to the extent that such communications are rendered indistinguishable from noise or require an unacceptable number of expensive or complex repeaters.
Indeed, in situations where cable, pressure pulse and wireless electromagnetic and acoustic communications are unavailable or ineffective, a separate, mechanically based interventional application is required for actuation of a downhole tool. So, for example, rig operations may be halted, surface equipment rigged up for a new intervention, and one or more packer setting applications carried out. This would then be followed by retrieval of interventional tools followed by re-establishing of production equipment and operations. Of course, all of this may halt operations for anywhere between hours and days, thereby driving costs up by tens if not hundreds of thousands of dollars. Nevertheless, where cable and pressure pulse communications are either unavailable or ineffective, operators are presently left with no viable alternative to such costly single shot interventions.
A method of actuating a downhole tool at a location in a well is detailed. The method is directed from the oilfield surface and includes sending a fluid-flow signal therefrom. The fluid-flow signal is detected at a flow meter in the well which is coupled to an actuator via appropriate signal processing, control and power circuitry. A tool disposed at the noted location may thus be actuated by the actuator. A completions assembly is also detailed which utilizes an application tool for performing an application in the well as driven by an actuation tool of the assembly. Thus, a trigger that is responsive to fluid-flow communication from the oilfield surface is also provided which is coupled to the actuation tool in order to initiate the driving of the application.
Embodiments herein are described with reference to certain downhole completions assemblies and operations. For example, assemblies are depicted herein that make use of packers for downhole isolation. However, a variety of alternate applications may take advantage of embodiments of actuating tools and techniques detailed herein. For example, actuations may relate to opening and closing barrier valves or shifting sliding sleeves. Furthermore, control over downhole fluid samplers or measurement recording devices may be exercised through such actuations. Even pyrotechnic devices such as perforators may be actuated according to techniques described herein. Regardless, the particular application, however, fluid-flow communication directed from surface may be utilized to initiate the actuation thereof.
Referring now to
In the embodiment shown, the completions assembly 100 is also equipped with an actuation tool in the form of a hydrostatic set module 150. The hydrostatic set module 150 uses hydrostatic pressure from the well relative to atmospheric pressure to displace a piston and perform work. However, alternative forms of actuation tools may be employed. Perhaps more notably, the assembly is also equipped with a fluid-flow trigger 137. That is to say, the trigger 137 is activated by way of fluid-flow communication which is generated at surface as detailed hereinbelow. Indeed, the trigger 137 includes a flow meter mechanism 135 along with an electronics and power housing 130 which are coupled to the module 150. The module 150 is in turn coupled to the packer 175 via a hydraulic line 160.
Referring now to
Continuing with reference to
Setting of the packer 175 via the fluid-flow 201 may be initiated by a pump 265 as directed by a control unit 260 disposed at the surface of the oilfield 200. Indeed, a host of surface equipment 225 may be disposed at surface for directing packer setting along with a variety of other oilfield operations. As shown, a rig 230 is provided to support initial completions operations as well as any number of subsequent interventions and related equipment. Further, the noted control unit 260 and pump 265 are coupled to a well head 250 which not only mediates the fluid-flow 201 but also plays a role in recovery of production fluid. Note the production line 255 also emerging from the well head 250. Alternatively, for deepwater or subsea applications, the pump 265 may be coupled to a well head 250 situated at the seabed.
As detailed further below, the fluid-flow 201 may be made to occur in detectable rates or signature patterns that allow for the directing of downhole equipment such as the module 150 via the indicated trigger 137. Indeed, additional triggers and equipment may be provided downhole such that multiple uniquely different fluid-flow commands may be separately utilized to direct a host of different downhole actuations of the same assembly 100. Similarly, multiple triggers 137 may be provided to direct the same actuation, such as setting of the packer 175 as depicted. Thus, a degree of fail-safe redundancy may easily be added to the system.
Referring now to
Referring specifically to
As shown in
The calorimetric-based flow-meter 135 of
In terms of accuracy, a flow-meter 135 utilizing calorimetric detection equipment 335 may effectively detect the rate of fluid-flow 201 to within about 10% accuracy for conventional downhole fluids such as water, brine and acid. Once more, in an alternate embodiment, a degree of accuracy may be attained even where the calorimetric detection equipment 335 includes a heat source 339 without the presence of sensors 337, 338. That is, electronics 130 of the trigger 137 or elsewhere may be utilized to monitor the amount of power required to maintain the heat of the thermal resistor source 339 at a predetermined level. For example, this may be achieved by supplying the resistor source 339 with a constant voltage while measuring the current maintaining that voltage. Thus, such power data may be translated to provide information regarding the rate of fluid-flow 201 within the tubing 110.
Referring now to
Referring to both
Continuing with reference to
Referring now to
With specific reference to
With reference to both
Additionally, triggering of the setting may require that the fluid-flow 201 employed be of a particular signature. Thus, the odds of accidental misfiring may be reduced. Indeed, in one embodiment, detection of the unique flow signature may result in a delayed actuation. In this manner, an operator may be provided with the opportunity to send a cancellation flow signature downhole.
Ultimately, with particular reference to
Referring now to
Continuing with reference to
Referring now to
For sake of power savings, the trigger may initially be utilized in a sleep mode with flow detections being periodic as noted at 650. However, as indicated at 660, a listening mode may be utilized upon encountering a predetermined set of criteria. Thus, fluid-flow activation as communicated from surface may be identified by the trigger (see 670). Ultimately, this identification may result in the initiating of a downhole actuation as indicated at 680, for example, the setting of a packer as detailed hereinabove.
In another embodiment, a built-in delay in advance of the actuation may be utilized in conjunction with the noted identification. In this manner, time may be allotted for an operator at surface to send a fluid-flow cancellation signal as indicated at 640. Thus, the pending downhole actuation may actually be terminated as indicated at 690. Of course, with such fluid-flow signaling available, any number of such communicative measures and countermeasures may be undertaken.
Referring now to
Embodiments described hereinabove allow for downhole actuations to be directed from surface even in circumstances where physical cables or fiber optics from surface are lacking and pressure pulse, electromagnetic or acoustic communication methods are unavailable or ineffective. These fluid-flow based communications also obviate the need for separate interventional applications in order to actuate downhole tools for particular applications. As a result, interruption of downhole operations is avoided along with the delays, risks and expenses of added rig-up time and the positioning of added large scale equipment. Thus, countless hours and dollars may be saved through use of the embodiments detailed herein.
The preceding description has been presented with reference to presently preferred embodiments. Persons skilled in the art and technology to which these embodiments pertain will appreciate that alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle, and scope of these embodiments. Furthermore, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.
