Oil and gas production with downhole separation and reinjection of gas
AssigneeConocoPhillips Company
InventorsJerry L. Brady, John M. Klein, Steven P. Petullo, Curtis G. Blount
Life of this patent
Estimating the term…
Abstract
A system (SPARC) for producing a mixed gas-oil stream wherein gas is to be separated and compressed downhole in a turbine-driven compressor before the gas is injected into a subterranean formation. A turbine bypass valve allows all of the stream to bypass the turbine during start-up until surging in the production stream has subsided. The valve then opens to allow a portion of the stream to pass through the turbine. Also, a compressor recycle valve recycles the compressor output until the surging in the stream has subsided while a check valve prevents back flow into the outlet of the compressor.
Claims19
A separator-compressor system (SPARC) adapted to be positioned downhole in a production wellbore wherein an annulus is formed between said SPARC and said wellbore, said SPARC adapted to separate and compress at least a portion of the gas from a mixed gas-oil production stream comprised of liquid, gas, and particulates as said stream flows upward through said wellbore;
- said separator-compressor system comprising:
- an upstream separator section for separating at least a portion of said production stream from the remainder of said stream;
- a turbine-compressor section positioned downstream from said upstream separator section;
- said turbine-compressor comprising:
- a turbine having an inlet and an outlet and adapted to be driven by said remainder of said stream;
- and
- a compressor having an inlet and an outlet and adapted to be driven by said turbine;
- and
- means for preventing surging in said turbine during start-up of said SPARC;
- and
- a downstream separator section positioned downstream from said turbine-compressor section.
A method for separating and compressing at least a portion of the gas in a mixed gas-oil production stream which is comprised of liquid, gas, and heavier components as said stream flows upward through a wellbore, said method comprising:
- positioning a separator-compressor system (SPARC) downhole within said wellbore whereby an annulus is formed between said SPARC and said wellbore;
- said SPARC having an upstream separator section, a turbine-compressor section, and a downstream separator section;
- opening said wellbore at the surface to allow flow of said production stream into said upstream separator section of said SPARC;
- bypassing all of said production stream from said upstream separator section around said turbine-compressor section until surging in said production stream has subsided;
- increasing the flow rate of said production stream through said wellbore;
- separating at least a portion of the heavier components of said production stream as said stream flows through said upstream separator section;
- separating the separated portion of the heavier components around said turbine-compressor section and directly the remainder of said production stream through said turbine-compressor section to drive the turbine therein;
- recombining said separated portion of the production with the remainder of the stream after the remainder of the stream as passed through said turbine;
- passing the combined stream through said downstream separator section to separate at least a portion of the gas in said stream from the remainder of the stream;
- flowing said separated gas to a compressor in said turbine-compressor section to thereby compress said gas;
- and
- flowing the compressed gas from said compressor into said annulus.
A separator-compressor system (SPARC) adapted to be positioned downhole in a production wellbore wherein an annulus is formed between said SPARC and said wellbore, said SPARC adapted to separate and compress at least a portion of the gas from a mixed gas-oil production stream comprised of liquid, gas, and particulates as said stream flows upward through said wellbore;
- said separator-compressor system comprising:
- an upstream separator section for separating at least a portion of said production stream from the remainder of said stream;
- a turbine-compressor section positioned downstream from said upstream separator section;
- said turbine-compressor comprising:
- a turbine having an inlet and an outlet and adapted to be driven by said remainder of said stream;
- and
- a compressor having an inlet and an outlet and adapted to be driven by said turbine;
- and
- means for preventing surging in said turbine during start-up of said SPARC, said means comprising at least one by-pass passage passing around said turbine and said compressor;
- and a turbine bypass valve for directing both said separated portion of said stream and said remainder of said stream into said by-pass passage when said turbine bypass valve is in a open position and for directing said separated portion of said stream through said by-pass passage and said remainder of said stream through said turbine when said turbine bypass valve is in a closed position;
- and
- a downstream separator section positioned downstream from said turbine-compressor section.
Dependencies are inferred from the claim text.