Methods including deactivation and activation of permeability modifiers for use in subterranean formation operations. A first treatment fluid may be introduced into a subterranean formation having a first treatment zone having a first aqueous permeability value, the first treatment fluid comprising a first aqueous base fluid and a deactivated permeability modifier. The deactivated permeability modifier may be adsorbed onto a surface of the first treatment zone. A second treatment may thereafter be introduced into the subterranean formation, the second treatment fluid comprising a second aqueous base fluid and a cyclodextrin compound. The second treatment fluid may contact the deactivated permeability modifier to activate the permeability modifier by complexing the deactivating surfactant with the cyclodextrin compound, thereby forming an activated permeability modifier adsorbed onto the surface of the first treatment zone and reducing the aqueous permeability of the first treatment zone.

Disclosed are compositions and methods for the pressure protection of existing wells during infill drilling operations.

A method and apparatus for producing hydrocarbons from a subterranean formation. A first well is provided in the formation, the first well being separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A second well is provided in the formation. The second well is separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A first fracture is provided in the formation, the first fracture extending substantially between the first zones. A second fracture is provided in the formation, the second fracture extending substantially between the second zones of the first and second wells. A fluid is injected into the formation from the first zone in the first well. Hydrocarbons are produced at the second zone of the second well.

Various examples are provided related to airlift pumping of downhole geothermal fluids. In one example, an airlift system includes a compressor; a gas sparger head in a wellbore of a geothermal well, and a pressure head recycle assembly. The sparger head produces artificial lift of the geothermal fluids by injecting a gas resulting in a difference in density downhole. The entrained gas can be extracted by the pressure head recycle assembly, compressed, and reinjected downhole. The geothermal fluid at the well head can be used in direct use applications or in a thermodynamic cycle to make shaft power. The gas sparger head can include a venturi shaped passage extending through the gas sparger head and a bubble orifice including gas orifices radially spaced about a narrow portion of the venturi shaped passage. The gas orifices can have a corresponding resonant chamber through which the gas (e.g., air) is provided.

Oil recovery can include providing a tubing string and isolation devices to define isolated intervals for an existing well previously operated using plug-and-perf and primary production. Valve assemblies are installed in respective isolated intervals, each valve assembly including at least two valves. The valve can be operated in open and closed configurations, and at least one open configuration provides choked flow via an elongated passage. The valves can have a housing and a shiftable sleeve. The valve assemblies can be operated to provide a desired openness based on the injectivity or other properties by shifting the sleeves of the valves. Different flow resistance levels can be provided to facilitate enhanced operations for water flooding and other oil recovery processes.

A method of performing measurements of an earth formation includes disposing at least a first receiver and a second receiver in one or more monitoring boreholes in a formation, and injecting fluid into the formation from an injection borehole, wherein injecting includes operating a fluid control device to generate seismic and/or acoustic noise having an identifiable characteristic. The method also includes detecting seismic and/or acoustic signals at the first receiver and detecting seismic and/or acoustic signals at a second receiver, the seismic and/or acoustic signals corresponding to the seismic and/or acoustic noise, calculating an estimate of a Green's function between the first receiver and the second receiver by processing seismic and/or acoustic waves detected by the first receiver and the second receiver to at least partially reconstruct the Green's function, and estimating variations in a velocity of a region of the formation by determining variations in the reconstructed Green's function.

Methods of enhanced oil recovery are disclosed that use compositions including an alkyl polyether anionic surfactant having the general structure R.sup.1JA, wherein R.sup.1 is a C.sub.8-C.sub.18 primary or secondary radical group, J is a random, block, alternating, or alternating block polyether segment having the structure [(PO).sub.x(EO).sub.y(BO).sub.z], wherein x is 4 to 18, y is 0 to 20, and z is 0 to 5, and A is an anionic group; a co-surfactant having the general structure (R.sup.2).sub.q(B)Ph-L-Ph(D)(R.sup.3).sub.r, wherein R.sup.2 and R.sup.3 are each, independently in each instance, a C.sub.8-C.sub.24 linear or branched, primary or secondary alkyl group, B and D are anionic groups, q is 1 to 3, r is 1 to 3, and L is O or CH.sub.2; and an alkoxy alcohol.

A monitoring system operable to monitor an oilfield additive system having multiple components. The oilfield additive system is operable to transfer an additive-containing substance for injection into a wellbore. The monitoring system includes sensors each associated with, and operable to generate information related to an operational parameter of, a corresponding one of the oilfield additive system components. The monitoring system also includes a monitoring device in communication with the sensors and operable to record the information generated by the sensors to generate a database. The database includes information indicative of maintenance aspects of the oil-field additive system and/or the oilfield additive system components.

A method of servicing a subterranean formation comprising providing a wellbore penetrating the subterranean formation and having a casing string disposed therein, the casing string comprising a plurality of points of entry, wherein each of the plurality of points of entry provides a route a fluid communication from the casing string to the subterranean formation, introducing a treatment fluid into the subterranean formation via a first flowpath, and diverting the treatment fluid from the first flowpath into the formation to a second flowpath into the formation.

A method of detecting a flood front through a subterranean formation, comprising, measuring a distance to the flood front, processing the measured distance using a predictor-corrector filter to determine a corrected distance to the flood front, and adjusting a formation device based on the corrected distance to control a flow of the flood front.