Oil and Gas Terms Beginning with “R” — Page 5

The volume percent (or fraction) of a mud that is not captured in the receiver when performing the water, oil and solids test as prescribed by API, as given in the equation below. Retort solids thus include suspended… Read more →

A type of downhole isolation tool that may be unset and retrieved from the wellbore after use, such as may be required following treatment of an isolated zone. A retrievable bridge plug is frequently used in combination… Read more →

A perforating gun designed to be retrieved from the wellbore after firing. Retrievable guns are generally configured for minimal debris and distortion of the gun body to help ensure easy retrieval. Read more →

A type of packer that is run and retrieved on a running string or production string, unlike a permanent production packer that is set in the casing or liner before the production string is run. Retrievable packers are… Read more →

The accumulation of sequences by deposition in which beds are deposited successively landward because sediment supply is limited and cannot fill the available accommodation. Thus, the position of the shoreline migrates… Read more →

What Is Retrograde Condensation? Retrograde condensation is the counterintuitive thermodynamic phenomenon in which a hydrocarbon gas mixture forms liquid droplets as pressure is reduced at constant temperature — the… Read more →

Mud that comes back to the surface and exits through the flowline after being pumped down the drillpipe. "Lost returns" is the situation in which some or all of the mud does not come back to the surface, which indicates… Read more →

To circulate fluid down the wellbore annulus, with returns being made up the tubing string. Reverse circulation often is used to remove debris from the wellbore since the high fluid flow rate inside the tubing string… Read more →

A type of in-situ combustion in which the burning front moves in an opposite direction to the injected air. Initially, air is injected into a production well and the fire is ignited. After the burning front has advanced… Read more →

A type of fault formed when the hanging wall fault block moves up along a fault surface relative to the footwall. Such movement can occur in areas where the Earth's crust is compressed. A thrust fault, sometimes called… Read more →

A downhole tool that is designed to enable communication between the tubing internal diameter and the annulus, typically for reverse circulation purposes, although conventional circulation often can also be undertaken.… Read more →

One of several flow characteristics of a material, such as a drilling fluid, completion fluid, workover fluid or cement. Shear-stress measurements made at a minimum of two shear rates are needed to define the properties… Read more →

The science and study of the deformation and flow of matter. The term is also used to indicate the properties of a given fluid, as in mud rheology. Rheology is an extremely important property of drilling muds, drill-in… Read more →

An additive for oil- and synthetic-base muds that provides high viscosity at low shear rates, which is useful when drilling high-angle and horizontal wells and can be critical for cuttings carrying and to prevent sag… Read more →

The most compact arrangement in space of uniform spheres (atoms and molecules in mineral crystals, or grains in sedimentary rocks) that results in a structure having no more than 26% porosity. Rhombohedral packing is… Read more →

Natural gas containing heavier hydrocarbons than a lean gas. Its liquid content adds important economic value to developments containing this type of fluid. Read more →

Gas condensate comprising significant amounts of heavy hydrocarbon products, which can produce relatively large volumes of condensate. Read more →

In a glycol dehydrator, glycol that contains water released by wet gas while percolating upward in the absorber. Read more →

Lean oil that has absorbed heavier hydrocarbon components from a gas stream Read more →

To pull apart the Earth's crust. Read more →

The machine used to drill a wellbore. In onshore operations, the rig includes virtually everything except living quarters. Major components of the rig include the mud tanks, the mud pumps, the derrick or mast, the… Read more →

To take apart equipment for storage and portability. Equipment typically must be disconnected from power sources, decoupled from pressurized systems, disassembled and moved off the rig floor or even off location. Read more →

The relatively small work area in which the rig crew conducts operations, usually adding or removing drillpipe to or from the drillstring. The rig floor is the most dangerous location on the rig because heavy iron is… Read more →

To make ready for use. Equipment must typically be moved onto the rig floor, assembled and connected to power sources or pressurized piping systems. Read more →

The characteristic of a cementslurry whose consistency changes from the point of departure or 30 Bc to 100 Bc in a short time. The term refers to the characteristic 90-degree bend in a plot of cement consistency versus… Read more →

The right that other parties to a lease, well, unit and/or concession have to acquire the interest that a selling party owns prior to selling to any third party. Read more →

The characteristic of a cementslurry whose consistency changes from the point of departure or 30 Bc to 100 Bc in a short time. The term refers to the characteristic 90-degree bend in a plot of cement consistency versus… Read more →

A well-intervention operation conducted with equipment and support facilities that precludes the requirement for a rig over the wellbore. Coiled tubing, slickline and snubbing activities are commonly conducted as… Read more →

The resistivity measured by the ring of a measurements-while-drilling (MWD) toroid device. The ring resistivity is a focused measurement with a depth of investigation and a vertical resolution of a few inches. It is not… Read more →

A type of bimetallic corrosion. Ringworm corrosion has the shape of a ring and is located a few inches from the pipe upset. The ring can either be very smooth or have severe pitting.Ringworm corrosion is caused by the… Read more →