A plunger lift system includes a bumper assembly to reduce the impact of the plunger at the bottom of the well and in some circumstances to reconfigure the plunger for the plunger's next ascent. The bumper assembly has a spring, a mandrel, an impact head, and a flow cage. The impact head and mandrel are constructed from a single piece of material thereby removing a joint between the impact head and mandrel. The unitary impact head/mandrel is connected to the flow cage using a first cooperating shoulder at the lower end of the unitary impact head/mandrel and a second cooperating shoulder within the flow cage. The first cooperating shoulder and the second cooperating shoulder are held in place with respect to each other by a force provided by the spring.

A bypass plunger includes a unibody, or one-piece hollow body and valve cage, retains a dart valve within the valve cage portion using a threaded retaining nut secured by crimple detents, and includes sealable flow parts. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during descent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and surfaced valve stems surfaced.

A plunger includes a sleeve having a passage therethrough and a valve member in the passage. When the plunger falls in a production string of a hydrocarbon well, the valve member is open and allows gas flow through the plunger. When the plunger contacts a liquid slug in the production string, the valve closes so that pressure from below reverses movement of the plunger so it pushes liquid above the plunger toward the earth's surface and ultimately to a well head where liquid and gas are separated.

A downhole tool movement control system and method of use, such as a movement control system to control the speed of a plunger tool when operating within a tubing string of a wellbore, such as when rising within a tubing string of a wellbore. In one embodiment, the downhole tool movement control system includes a system controller operating to control a system valve to regulate the plunger tool speed, the system controller settings based on a set of system parameters.

Methods and systems for increasing normalized production rate of an oil and gas reservoir by optimizing a pressure drawdown of a subsurface formation are disclosed. The methods include determining permeability of the subsurface formation as a function of effective stresses, determining a stress sensitivity factor for the core sample, upscaling the sensitive stress factor, determining the optimum pressure drawdown for the subsurface formation, and controlling the pressure drawdown in a field operation such that it does not exceed the optimum pressure drawdown for the subsurface formation.

A system for producing hydrocarbons from a subterranean well including a wellbore extending from a surface into a subterranean formation includes a wellhead disposed at the surface. In addition, the system includes a production tree coupled to the wellhead and a casing coupled to the wellhead and extending into the wellbore. Still further, the system includes a first production tubing string extending into the casing from the wellhead to a first production zone and a second production tubing string extending into the casing from the wellhead to the first production zone. The first production tubing string and the second production tubing string are each configured to provide a fluid flow path for gases from the first production zone. The second production tubing string is radially spaced from the first production tubing string. The first production tubing string has an inner diameter D1 that is larger than an inner diameter D2 of the second production tubing string.

In some embodiments, an apparatus and a system, as well as a method and article, may operate to identify one or more multiphase fluid flow regimes as an output of fuzzy logic processing, with inputs to the fuzzy logic processing comprising a set of physical parameter values as attributes at a location in a fluid flow that are determined by at least one of measurement or simulation, and to operate a controlled device based on the output. Additional apparatus, systems, and methods are disclosed.

Downhole pumps may include, at the inlet, a component that reduces the amount of water taken up by the pump. For example, a downhole assembly may include a tool string that includes a fluid pump, a fluid intake subassembly, a motor, and a downhole control system each coupled such that a fluid flowing into the fluid intake assembly is conveyed to the fluid pump; one or more inlets defined in the fluid intake subassembly; a flow line fluidly coupled to at least one of the one or more inlets and containing a filter component that contains a filter media at least partially coated with a relative permeability modifier (RPM), wherein the fluid flowing through the flow line contacts the RPM.

A carbon-based gas extraction and storage system is described that includes a coal bed methane (CBM) energy production facility. A first well includes a first pump configured operate in an extraction mode in which methane from the CBM chamber is pumped from a CBM chamber, and convertible to an insertion mode in which CO2 is pumped into the CBM chamber. The second well extracts CBM from the CBM chamber. A controller controls the first pump to operate in the extraction mode and controllably switch to the insertion mode in which CO2 emissions from CBM processed by the CBM energy production facility are injected in the CBM chamber. Thus, first pump injects the CO2 emissions into the CBM chamber to assist in extraction of CBM and to permanently store the CO2 in the CBM chamber.

Described herein are embodiments of systems and apparatuses that include a dart and/or a clutch for a dart plunger. In an exemplary embodiment, the clutch consists of a one-piece unit having a length, an outside diameter, and an inside diameter where at least a portion of the inside diameter is sized to create a frictional interface with a dart. The clutch may also include a gap, a slot, and/or a spiral cut. The dart may include a shaft having opposite ends and a shaft diameter that varies between the opposite ends.