A method of drilling multiple boreholes within a single caisson, for recovery of methane gas from a coal bed, including the steps of drilling first and second vertical boreholes from a single location within a single caisson; drilling at least one or more horizontal wells from the several vertical bore hole, the horizontal wells drilled substantially parallel to a face cleat in the coal bed; drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and entrained methane gas from the coal bed; applying friction or choke manifold to the water circulating down the well bores so that the water appears to have a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water obtained from the lateral wells into a water zone beneath the surface.

Disclosed is an oil extraction and gas production method capable of in-situ sand control and removal by downhole hydraulic lift achieved by downhole oil extraction and gas production system and ground oil extraction and gas production system. The downhole systems mainly comprises a double-layer tube, a double-layer tube reducing joint, a double-layer tube packer, a hydrodynamic turbine motor, a sludge screw pump, a soil-sand separator and a negative pressure absorber; the ground system comprises a power fluid pressurizing module and a mix fluid treatment module. The present application lowers the difficulty of pumping and lifting downhole formation fluid; achieves downhole and in-situ sand control and sand discharge, alleviates the blockage and erosion of sand particles on equipments and reduces energy consumption; decreases the production cost and improves the operation efficiency, therefore is suitable for oil extraction and gas production in high sand content wells.

A method of drilling multiple boreholes within a single caisson, for recovery of methane gas from a coal bed, including the steps of drilling first and second vertical boreholes from a single location within a single caisson; drilling at least one or more horizontal wells from the several vertical bore hole, the horizontal wells drilled substantially parallel to a face cleat in the coal bed; drilling at least one or more lateral wells from the one or more horizontal wells, the lateral wells drilled substantially perpendicular to one or more face cleats in the coal bed; continuously circulating water through the drilled vertical, horizontal and lateral wells to recover the water and entrained methane gas from the coal bed; applying friction or choke manifold to the water circulating down the well bores so that the water appears to have a hydrostatic pressure within the well sufficient to maintain an equilibrium with the hydrostatic pressure in the coal bed formation; and drilling at least a third vertical borehole within the single caisson, with one or more horizontal boreholes and one or more lateral boreholes for returning water obtained from the lateral wells into a water zone beneath the surface.

Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.

Systems and methods include a computer-implemented method for determining a gas-oil rate (GOR) for an oil well. A measured GOR is determined for an oil well. A measured water cut (WC) is determined for the oil well. An initial solution of the GOR is determined for the oil well. A corrected WC is determined for the oil well based on a function of the measured GOR, the measured WC, and the initial solution of the GOR.

A submersible pump system may include a perforated casing lining a wellbore adjacent to a first formation and a second formation. Additionally, a production tubing may be hanging in the wellbore to extend past the first formation and into the second formation to form a fluid conduit from a surface to the second formation. Further, an electrical submersible pump may be coupled to the production tubing and be oriented upside-down to have one or more fluid intakes at an upper end of the electrical submersible pump and one or more fluid outlets at a lower end of the electrical submersible pump. The electrical submersible pump may be positioned downhole in the wellbore between the first formation and the second formation. The upside-down electrical submersible pump may be configured to extract fluid from the first formation and inject the extracted fluid into the second formation with the production tubing.

The present invention relates to a group and method for the separation of a mixture comprising two fluid phases mutually at least partially immiscible and with different specific density characterized in that it comprises a closed chamber (11) which extends between an upper outlet mouth (12a) of a fluid phase with lower specific density separated from the mixture, positioned at a first upper height, and a lower outlet mouth (12b) of a fluid phase with greater specific density separated from the mixture, positioned at a second lower height with respect to the first upper height, an inlet (15,33) for said mixture inside said closed chamber (11) also being present at a height interposed between said upper and lower heights, a first upper gross separation device (13) of said mixture and a second lower fine separation device (14,14′) of said mixture, hydraulically connected to each other (13) (14), being situated in succession, inside said closed chamber (11), between said upper outlet mouth (12a) and said lower outlet mouth (12b), the first upper gross separation device (13) comprising a gravitational separation chamber and the at least second lower fine separation device (14,14′) comprising at least one coalescence separator (14) and/or at least one hydrocyclone separator (14′).

Embodiments of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. One embodiment comprises adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.

A water separation system includes a production control valve fluidly connected to a production tubing and positioned at an uphole end of the production tubing at a well head of a well site, a production fluid pathway between the production control valve and a water separator, an injection control valve fluidly connected to an injection tubing and positioned at an uphole end of the injection tubing at the well head, and an injection fluid pathway between the injection control valve and the water separator. The water separator is positioned at the well site and is fluidly connected to the production fluid pathway and the injection fluid pathway. The water separator separates water from the production fluid and directs the separated water to the injection fluid pathway. An output fluid pathway fluidly connects to the water separator to direct the production fluid out of the water separator.

A submersible pump system may include a perforated casing lining a wellbore adjacent to a first formation and a second formation. Additionally, a production tubing may be hanging in the wellbore to extend past the first formation and into the second formation to form a fluid conduit from a surface to the second formation. Further, an electrical submersible pump may be coupled to the production tubing and be oriented upside-down to have one or more fluid intakes at an upper end of the electrical submersible pump and one or more fluid outlets at a lower end of the electrical submersible pump. The electrical submersible pump may be positioned downhole in the wellbore between the first formation and the second formation. The upside-down electrical submersible pump may be configured to extract fluid from the first formation and inject the extracted fluid into the second formation with the production tubing.