TELEMETRIC CHEMICAL INJECTION ASSEMBLY
A chemical injection assembly with telemetric capacity and a single fluid injection line capable of reaching multiple downhole injection points. The assembly may take advantage of downhole power telemetry modules so as to intelligently power and direct actuator valves at any of a number of different injection points. So, for example, the need for cumbersome and expensive usage of different delivery lines dedicated to serve different delivery points with the same fluid may be avoided.
This Patent Document is a Continuation-In-Part claiming priority under 35 U.S.C. §120 to U.S. application Ser. No. 13/364,785, entitled “Chemical Injection Regulation Mechanism”, filed Feb. 2, 2012, and which claims priority under 35 U.S.C. §119 to U.S. Provisional App. Ser. No. 61/438,995, filed on Feb. 3, 2011, and entitled, “Chemical Injection U-Tube Prevention System”, both of which are incorporated herein by reference in their entireties.
BACKGROUNDExploring, drilling and completing hydrocarbon wells are generally complicated, time consuming and ultimately very expensive endeavors. As a result, over the years increased attention has been paid to monitoring and maintaining the health of such wells. Significant premiums are placed on maximizing the total hydrocarbon recovery, recovery rate, and extending the overall life of the well as much as possible. Thus, logging applications for monitoring of well conditions play a significant role in the life of the well. Similarly, significant importance is placed on well intervention applications, such as clean-out techniques which may be utilized to remove debris from the well so as to ensure unobstructed hydrocarbon recovery.
In addition to interventional applications, the well is often outfitted with chemical injection equipment to enhance ongoing recovery efforts without the requirement of intervention. For example, most of the well may be defined by a smooth steel casing that is configured for the rapid uphole transfer of hydrocarbons and other fluids from a formation. However, a buildup of irregular occlusive scale, wax and other debris may occur at the inner surface of the casing or tubing and other architecture so as to restrict flow. Such debris may even form over perforations in the casing, screen, or slotted pipe thereby also hampering hydrocarbon flow into the main borehole of the well from the surrounding formation.
In order to address the potential for scale and other buildup as noted above, time consuming interventional applications may be avoided through use of a circulating chemical injection system. With such systems in place, a metered amount of chemical mixture, such as a hydrochloric acid mix, may be near continuously circulated downhole to help prevent such buildup. This equipment includes an injection line that may be run from surface and directed at different downhole points of interest such as within production tubing, at a production screen or into formation fluid prior to entering the noted tubing. Regardless, the need to halt production or run expensive interventions in order to address undesirable buildup may be largely eliminated.
Unfortunately, unlike more interactive interventions, chemical injection faces a variety of limitations in terms of delivery. For example, the permanently installed hydraulic line generally terminates at a port below an area of concern such as the indicated production screen. However, this delivery is targeted at a single release point with the system relying on circulation of the delivered chemical mix in order to reach any other locations. Thus, even though a variety of locations may be of potential concern, only the target location is ensured of receiving the intended mix with a notable degree of precision.
With the limitations of single port delivery in mind, there are circumstances in which the delivery line is outfitted with multiple delivery ports such that delivery to more than one location is not limited to sole reliance on circulation. However, in these situations, the versatility of the delivery nevertheless remains limited. For example, where delivery is directed at multiple production zones, there may be particular zones of concern at one point in time and other zones of interest at other times. Yet, with a single delivery line available, each port delivers a predetermined rate of chemical mix when directed from surface equipment. That is to say, different ports at different locations are generally unable to activated while others are left closed. Rather, by way of a single delivery line, all ports are generally on or all are turned off.
Of course, it may be possible to provide a dedicated delivery line for each port which runs from surface equipment. In this manner, each line may be independently turned on or off at surface so as to allow for downhole ports to be independently activated. However, this type of system would require a dedicated delivery line for each and every port, thus, dramatically increasing completions equipment and installation expense.
As an alternative to providing a dedicated line running to each port where multiple ports are utilized, isolation techniques may be employed. That is, as in the case of stimulation and other zonally directed applications, different downhole zones may be isolated for sake of targeted delivery. In such cases, packers or other isolating downhole features may be employed as a means of targeting chemical injection delivery from multiple ports. For example, one downhole region may be isolated in a manner that prevents chemical delivery thereto while allowing such delivery elsewhere. Of course, again, shutting down production for sake of attaining isolation results in applications that are no more cost-effective or time saving than the original types of interventions which chemical injection systems are configured to help avoid.
Ultimately, dedicated delivery lines and isolation techniques are usually avoided. As a matter of time and cost, such options remain largely impractical. Thus, operators are generally left with reliance on single or multi-point chemical injection delivery which lacks any real measure of control over location specific delivery and/or adjustment thereto.
SUMMARYA “smart” chemical injection assembly utilizing telemetry is provided. The assembly includes a mandrel housing coupled to a downhole tubular with an electric line that runs from an oilfield surface to the mandrel in a land well or offshore well. A fluid injection line is provided that also runs from the oilfield surface to the mandrel in a land well or offshore well. Further, a power telemetry module is coupled to the electric line. Thus, an electric actuator that is coupled to the injection line may be provided for governing fluid injection. Additionally, one or both of the module and the actuator may be secured within the mandrel housing.
Embodiments are described with reference to certain configurations of completions hardware that make use of chemical injection assemblies. In particular, completions are depicted and described which utilize a chemical injection assembly to help prevent scale and other buildup in a manner that may be telemetrically directed. For example, different injection points in different well locations may be independently directed from an oilfield surface even though a common injection line may be utilized. Of course, a variety of different completion architectures may benefit from utilization of such an injection assembly. For example, even a system utilizing a single injection point may benefit from telemetrically directed injection. Regardless, an injection sub (or mandrel housing) is provided that is equipped to accommodate either, or both, of an actuator valve to govern injection and a power module. Thus, the valve may be directly and independently powered and controlled via telemetric and fluid injection lines running thereto from surface.
Referring now to
Zonal isolation at production regions 190, 195 as described above may allow for tailored recovery of production fluids. For example, the tubular 107 may be outfitted with a separate flow control valve 115, 116, exposed to the isolated annular space 105, 106. Thus, a hydraulic or other suitable control line 117 may be utilized to independently open or close the valves 115, 116. As such, production through a slotted liner 187, screen, perforated liner or similar hardware where utilized, at either formation region 190, 195 may be regulated via the open or closed valve 115, 116.
Continuing with reference to
Further, while it might be possible to supply each valve 160, 162 with its own dedicated fluid line which may be controlled from the oilfield surface 300, this may be extremely cost prohibitive (see
The telemetric line 155 of
Referring now to
Continuing with reference to
As described above, the independent control over chemical injection delivery is directed through a telemetric line 155. This may be a conventional electronic or other suitable cable. Once more, the line 155 may be routed from surface to a power telemetry module 171 as detailed above. That is, the module 171 may serve a function of acquiring and relaying data relative to temperature, pressure and perhaps other location-based well characteristics (note the exposed outlet to the tubular channel 103). However, the module 171 may also advantageously serve the added function providing power and communicative relay to the injection valve 162 (note the electrical branch 255 of the line 155 routed to the valve 162). Thus, independent control over the valve 162 may be exercised from the oilfield surface 300. Indeed, with multiple modules 170, 171 available, this same type of telemetric layout may be repeated at multiple downhole subs 101, 102 (see
Referring now to
Continuing now with reference to
In the embodiment of
Continuing with reference to
Referring now to
Keeping fluids separated from one another may be desirable where the different fluids serve different applications, for example, different chemical injection and stimulation applications as noted above. However, it is worth noting that the added secondary line 400 is not required for sake of delivery to different injection points 161, 163 (see
Referring now to
In the embodiment of
Referring now to
Embodiments described hereinabove include a telemetric or “smart” chemical injection assembly which is able to provide targeted chemical injection at multiple downhole depths or locations in a tailored manner. That is, without the requirement of a multitude of individually dedicated chemical injection lines, multiple delivery locations may be independently regulated for delivery from an oilfield surface. Further, no intervening isolations are required in order to achieve such targeted or tailored delivery. Indeed, one downhole location may be opened and serviced while another remains turned off and vice versa. This may be achieved in a cost-effective manner through the use of available power telemetry modules.
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. Regardless, 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.
Claims
1. A telemetric chemical injection assembly for disposal in a well at an oilfield, the assembly comprising:
- an injection sub;
- an actuator valve disposed within said sub to govern fluid injection therefrom;
- a power and telemetry module coupled to said valve;
- a telemetric line configured to run from a surface of the oilfield to said module; and
- a fluid injection line configured to run from a surface of the oilfield to said valve for the fluid injection.
2. The assembly of claim 1 wherein said module is disposed within said sub.
3. The assembly of claim 1 wherein said module serves as a monitor for well conditions.
4. The assembly of claim 3 wherein the well conditions include one of pressure and temperature.
5. The assembly of claim 1 wherein said actuator valve is electrically powered via said module.
6. The assembly of claim 1 wherein said actuator valve is selected from a group consisting of a plunger valve, a sliding sleeve, a gas lift valve, a solenoid valve, an electric motor and a metering valve.
7. The assembly of claim 1 wherein the fluid injection line is configured to supply a chemical injection fluid mix to said valve.
8. The assembly of claim 1 further comprising a secondary line configured to run from a surface of the oilfield to said valve for supplying of a secondary fluid.
9. The assembly of claim 8 wherein the secondary fluid is a stimulation fluid.
10. The assembly of claim 1 wherein said sub and said actuator valve are a first sub and a first actuator valve, the assembly further comprising a second actuator valve coupled to said injection line disposed within a second sub at a different depth of the well than said first sub.
11. The assembly of claim 1 wherein said valve is a first valve, the assembly further comprising a second valve coupled to said injection line within the sub.
12. A telemetric chemical injection system comprising for disposal in a well at an oilfield, the system comprising:
- a tubular with a channel running therethrough and disposed within the well, the well defined by multiple formation regions;
- a zonal isolation packer defining a first annulus thereabove and a second annulus therebelow, said packer positioned at a depth between at least portions of the regions;
- a first injection sub and power module coupled to said tubular within the first annulus;
- a second injection sub and power module coupled to said tubular within the second annulus;
- a telemetric line configured to run from a surface of the oilfield to said modules; and
- a fluid injection line configured to run from the oilfield surface to said subs.
13. The system of claim 12 further comprising:
- a first flow control valve incorporated into said tubular at a location of the first annulus; and
- a second flow control valve incorporated into said tubular at a location of the second annulus.
14. The system of claim 12 wherein said subs comprise actuator valves for delivery of fluid from the fluid injection line.
15. The system of claim 14 wherein the delivery is directed at one of the channel and a formation interface with the well.
16. A method of delivering chemical injection fluid to a well at an oilfield, the method comprising:
- directing an actuator valve to open from a surface of the oilfield over a telemetric line running therefrom:
- powering said directing through a power telemetry module coupled to the telemetric line and the valve; and
- supplying the fluid for the delivering through a fluid injection line coupled to the valve.
17. The method of claim 16 wherein the actuator valve is a first actuator valve, said directing further comprising maintaining closure of a second actuator valve coupled to the telemetric and fluid injection lines.
18. The method of claim 16 wherein the actuator valve is a first actuator valve, said directing further comprising opening a second actuator valve coupled to the telemetric and fluid injection lines.
19. The method of claim 16 further comprising supplying another fluid through a secondary injection line coupled to the valve for another application.
20. The method of claim 16 further comprising recovering fluids including the injection fluid through production to a surface at the oilfield.
Type: Application
Filed: Aug 1, 2012
Publication Date: Nov 22, 2012
Inventor: Dinesh R. Patel (Sugar Land, TX)
Application Number: 13/564,236
International Classification: E21B 34/06 (20060101); E21B 33/12 (20060101); E21B 34/00 (20060101);