Dual-purpose additives that may be used as viscosifying agents and surface active agents in fluids, subterranean treatments and oilfield operations are provided. In one embodiment, the methods comprise: providing a treatment fluid comprising a base fluid and a polymeric dual-purpose additive comprising a base polymer comprising a plurality of monomer units, and one or more hydrophobic groups bonded to at least one of the monomer units; introducing the treatment fluid into at least a portion of a subterranean formation; and depolymerizing at least a portion of the dual-purpose additive to form one or more surface active fragments, each of the surface active fragments comprising one or more of the hydrophobic groups bonded to one or more of the monomer units.

Dual-purpose additives that may be used as viscosifying agents and surface active agents in fluids, subterranean treatments and oilfield operations are provided. In one embodiment, the methods comprise: providing a treatment fluid comprising a base fluid and a polymeric dual-purpose additive comprising a base polymer comprising a plurality of monomer units, and one or more hydrophobic groups bonded to at least one of the monomer units; introducing the treatment fluid into at least a portion of a subterranean formation; and depolymerizing at least a portion of the dual-purpose additive to form one or more surface active fragments, each of the surface active fragments comprising one or more of the hydrophobic groups bonded to one or more of the monomer units.

In accordance with embodiments of the present disclosure, a gravel pack system includes a service tool used to maintain a pressure of the wellbore below a hydraulic packer at the same pressure of workstring tubing above the hydraulic packer, prior to and during setting the hydraulic packer. The service tool includes a washpipe disposed at a lower portion of the service tool, a crossover port in a wall of the service tool that enables fluid to flow between workstring tubing and a space between the service tool and a completion string. The service tool also includes a valve disposed in the wall of the service tool that directs fluid from the space between the service tool and the completion string into the service tool and toward the washpipe when the valve is open, the valve being closeable in response to compression of the service tool.

Methods and system for using salting out inhibitors in subterranean formations are provided. In some embodiments, the methods comprise introducing a treatment fluid comprising an aqueous base fluid, a salting out inhibitor, a gelling agent, and one or more salts into at least a portion of a subterranean formation, wherein the salting out inhibitor is selected from the group consisting of: an oligomer comprising one or more quaternary ammonium cations, a polymer comprising one or more quaternary ammonium cations, a source of one or more phosphate anions, and any combination thereof.

Methods and system for using salting out inhibitors in subterranean formations are provided. In some embodiments, the methods comprise introducing a treatment fluid comprising an aqueous base fluid, a salting out inhibitor, a gelling agent, and one or more salts into at least a portion of a subterranean formation, wherein the salting out inhibitor is selected from the group consisting of: an oligomer comprising one or more quaternary ammonium cations, a polymer comprising one or more quaternary ammonium cations, a source of one or more phosphate anions, and any combination thereof.

A technique facilitates formation of a gravel pack in a wellbore. Gravel slurry is delivered downhole to a desired gravel packing zone located along an annulus surrounding a gravel packing completion. Dehydration of the gravel pack is facilitated by providing a return flow path for a carrier fluid along drainage layers of adjacent screen assemblies. The drainage layers of adjacent screen assemblies are coupled by drainage layer shunt tubes which bypass corresponding couplings between the adjacent screen assemblies. In some applications, the drainage layer shunt tubes facilitate delivery of the returning carrier fluid to a sliding sleeve assembly.

A technique facilitates formation of a gravel pack in a wellbore. Gravel slurry is delivered downhole to a desired gravel packing zone located along an annulus surrounding a gravel packing completion. Dehydration of the gravel pack is facilitated by providing a return flow path for a carrier fluid along drainage layers of adjacent screen assemblies. The drainage layers of adjacent screen assemblies are coupled by drainage layer shunt tubes which bypass corresponding couplings between the adjacent screen assemblies. In some applications, the drainage layer shunt tubes facilitate delivery of the returning carrier fluid to a sliding sleeve assembly.

Provided herein is a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

Provided herein is a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

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.