Patent Application
20150041129
This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art.
Steam injection can be utilized to recover reservoir hydrocarbons. For example, steam may be injected into a subterranean formation through a first well and hydrocarbons produced from adjacent wells. In huff and puff or cyclic operations, steam is injected into a subterranean formation through a wellbore and after a period of time formation fluids are produced from the same well. In cyclic steam injection operations, a steam injection completion may be installed in the wellbore for steam injection and then pulled out of the wellbore when the steam injection is terminated. A production completion is then run into the wellbore when it is desired to place the well on production.
In accordance with some embodiments a completion for steam injection and production includes a production tubing connected to the stinger, a downhole steam generator (DSG) having a discharge connected to the production tubing through an inverted Y-tool, a fuel supply tubing extending between the DSG and a surface fuel supply and an air supply tubing extending between the DSG and a surface air supply. A method in accordance to some embodiments includes generating steam at a downhole steam generator incorporated in an upper completion that is deployed in a wellbore, injecting the steam into a formation, terminating steam generation and producing formation fluid through the upper completion. A well system includes a sequential steam injection to production completion installed in a wellbore.
The foregoing has outlined some of the features and technical advantages in order that the detailed description of the steam injection and production completion and methods that follows may be better understood. Additional features and advantages will be described hereinafter which form the subject of the claims of the invention. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of claimed subject matter.
Embodiments of sequential steam injection and production completions are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components. It is emphasized that, in accordance with standard practice in the industry, various features are not necessarily drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
As used herein, the terms “connect,” “connection,” “connected,” “in connection with,” and “connecting” are used to mean “in direct connection with” or “in connection with via one or more elements”; and the term “set” is used to mean “one element” or “more than one element”. Further, the terms “couple,” “coupling,” “coupled,” “coupled together,” and “coupled with” are used to mean “directly coupled together” or “coupled together via one or more elements”. As used herein, the terms “up” and “down”; “upper” and “lower”; “top” and “bottom”; and other like terms indicating relative positions to a given point or element are utilized to more clearly describe some elements. Commonly, these terms relate to a reference point as the surface from which drilling operations are initiated as being the top point and the total depth being the lowest point, wherein the well (e.g., wellbore, borehole) is vertical, horizontal or slanted relative to the surface.
Lower completion 20 may include a packer 26 (i.e. production packer) having a polished bore receptacle (PBR) 28 and a tail pipe 30 extending below packer 26. Lower completion may include an isolation device 32 such as a valve, flow control device, or nipple cooperative with a closure member 34. Closure member 34 is illustrated in
Upper sequential steam-production completion 22 includes a downhole steam generator (DSG) 36 (e.g. combustor) that utilizes a fuel such as natural gas or methane, and air to convert water to steam downhole for injection into formation 16. Upper completion 22 may include a control line 38 extending from the surface to one or more downhole devices. Control line 38 may be a cable, or umbilical, having more than one conduit for transmitting power and or signals. For example, control line 38 may include hydraulic conduits, electrical conductors, optic fibers and the like. In
Upper completion 22 in accordance to one or more embodiments includes a production tubing 42 extending from the wellhead to stinger 44 (seal assembly, stabber assembly) which is landed in PBR 28. Production tubing 42 may be a substantially continuous conduit incorporating an inverted Y-tool 46 between the surface and stinger 44. Inverted Y-tool 46 includes a first inlet flow path or leg 45 that is continuous with a single outlet flow path or leg 49 and a second inlet flow path or leg 47 that is combined into single outlet flow path 49. Production tubing 42 is connected to first leg 45 of inverted Y-tool 46 and is connected to stinger 44 through single leg 49.
Steam discharge 48 of DSG 36 is connected to stinger 44 through inverted Y-tool 46. Steam discharge 48 is connected to second leg 47 of inverted Y-tool 46 and connected to stinger 44 through single leg 49. Inverted Y-tool 46 is illustrated located adjacent to stinger 44 for the purpose of illustrating and describing other features of the sequential steam-production completion.
A valve 50 (e.g. check valve) is connected within steam discharge 48 between DSG 36 and inverted Y-tool 46 to prevent back flow into DSG 36 from below lower completion 20, e.g. formation fluid, or from production tubing 42. Production tubing 42 may include a barrier 52, for example a valve or retrievable plug, to selectively close production tubing 42 for example to prevent steam from being produced to the surface.
Upper completion 22 includes two tubing strings extending from surface to provide fuel and air to DSG 36. For example, fuel supply tubing 54 is deployed from wellhead 24 to DSG 36. Fuel supply tubing 54 is connected to a fuel supply 56 (e.g. natural gas, methane, hydrogen, etc.). Fuel source 56 may include a compressor. Air tubing 58 is deployed from wellhead 24 to DSG 36. Air tubing 58 is connected to an air source or supply 60 which may include a compressor. With reference to
In accordance to one or more embodiments, upper completion 22 may include an artificial lift device 68 for example as illustrated in
Fuel 56, air 60, and water 62 are supplied 120 to DSG 36. Controller 40 may be utilized to control the supply of fuel, air and water to DSG 36 and to operate DSG 36 to generate 130 steam 74. Steam 74 is exhausted through discharge 48 past valve 50 and through lower completion 20 and is injected into formation 16. Barrier 52 may be operated or activated in production tubing 42 to close the flow path during steaming operations. Barrier 52 is shown activated in
When steaming operations are completed DSG 36 may be shut-down 140 and the air, water, and fuel supplies to DSG 36 closed. In accordance to some embodiments, the well or formation 16 may be suspended for a period of time, i.e. soak period, before placing the well on production. During the soak period the production tubing may be closed by barrier 52 (e.g. plug 53) and valve 50 isolates DSG 36 from back flow of steam 74 and formation fluid 72. In accordance to embodiments, upper completion 22 is not pulled out of the wellbore while the well soaks.
The well is placed 150 on production for example by opening barrier 52. In accordance with one or more embodiments, completion 22 is not pulled out of the wellbore between termination 140 of steaming and or soaking operations and placing 150 the well on production. In the
In accordance to some embodiments, artificial lift (i.e. secondary lift) may be desired to produce formation fluid 72 to the surface. Artificial lift devices 68 incorporated in completion 22 may be operated 160 to aid in producing formation fluid 72 to the surface. In accordance to some embodiments, artificial lift device 68 may be a operated via control line 38. In some embodiments, artificial lift device 68 is a gas lift valve. Gas, for example supply 56, is directed from fuel supply tubing 54 into production tubing 42 through gas lift valve 68. In accordance to some embodiments, artificial lift device 68 is a jet pump. Power fluid, i.e. water 62, may be supplied for example from water tubing 66 or other locations. For example, DSG 36 may be operated to produce a hot effluent that may be directed from steam generator discharge 48 to artificial lift device 68. The hot effluent may be diverted from discharge 48 between DSG 36 and valve 50 whereby the hot effluent (e.g. steam 74) acts as gas lift mechanism for a thermal jet pump.
The foregoing outlines features of several embodiments of sequential steam injection to production completions and methods so that those skilled in the art may better understand the aspects of the disclosure. Those skilled in the art should appreciate that they may readily use the disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the disclosure. The scope of the invention should be determined only by the language of the claims that follow. The term “comprising” within the claims is intended to mean “including at least” such that the recited listing of elements in a claim are an open group. The terms “a,” “an” and other singular terms are intended to include the plural forms thereof unless specifically excluded.
This application claims the benefit of U.S. Provisional Patent Application No. 61/863,574, filed Aug. 8, 2013 entitled STEAM INJECTION AND PRODUCTION COMPLETION SYSTEM which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61863574 | Aug 2013 | US |
