Oil and Gas Terms Beginning with “T” — Page 6

A multiphase-fluid flow regime characterized by a chaotic mixture of liquid and gas, with neither phase appearing to be continuous. Also known as churn flow, transition flow is an intermediate flow condition between… Read more →

With reference to invasion, the volume between the flushed zone and the undisturbed zone in which the mudfiltrate has only partially displaced the moveable formation fluids. One common model of invasion assumes a smooth… Read more →

A technique used in crosswell seismic and electromagnetic tomography for recording the direct signal from the source or transmitter in one well to the receiverarray in another well. This technique is used for mapping… Read more →

The simultaneous occurrence of strike-slip faulting and compression, or convergence, of the Earth's crust. In areas of transpression, rocks can be faulted upward to form a positive flower structure. Areas of strike-slip… Read more →

The simultaneous occurrence of strike-slip faulting and extension, rifting, or divergence of the Earth's crust. In areas of transtension, rocks can be faulted downward to form a negative flower structure. Areas of… Read more →

A mode of the electromagnetic field that involves only one component of the electric field and the two components of the magnetic field perpendicular to it; e.g., the x-component of the electric field and y- and… Read more →

A mode of the electromagnetic field that involves only one component of the magnetic field and the two components of the electric field perpendicular to it; e.g., the x-component of the magnetic field and y- and… Read more →

The loss of coherent energy by protons in a rock while precessing about a static magnetic field during a nuclear magnetic resonance measurement. The loss of coherent energy, or relaxation, due to the free induction… Read more →

What Is a Trap in Oil and Gas? A trap in petroleum geology is a geometric configuration of reservoir rock and impermeable seal rock that prevents migrating hydrocarbons from escaping and causes them to accumulate into… Read more →

Oil in pore spaces that cannot be moved because of capillary forces. Typical trapped or residual oilsaturation is in the range of 10% to 50% of the pore space, and it is higher in tighter formations where the pore… Read more →

(noun) A section of tubing with a polished bore receptacle or seal assembly that permits relative axial movement between the tubing string and a downhole packer, accommodating thermal expansion, contraction, and… Read more →

The set of sheaves that move up and down in the derrick. The wire rope threaded through them is threaded (or "reeved") back to the stationary crown blocks located on the top of the derrick. This pulley system gives… Read more →

In a subsurface sucker-rod pump, the valve that closes the barrel chamber allowing the trapped fluid to be lifted in the upstroke of the pump. This valve is similar in configuration to the standing valve. Read more →

The slip set on a snubbing unit that is located at the top of the jack assembly. Two sets of travelling slips are available, one set for heavy-pipe conditions and another for light-pipe conditions. Read more →

The travelling slip set on a snubbing unit that is used when operating under light-pipe conditions. Under these conditions, the wellheadpressure is sufficient to eject the tubing string from the wellbore. Therefore, the… Read more →

The duration of the passage of a signal from the source through the Earth and back to the receiver. A time seismic section typically shows the two-way traveltime of the wave. Read more →

A vessel used to treat oil-water emulsions so the oil can be accepted by the pipeline or transport. A treater can use several mechanisms. These include heat, gravity segregation, chemical additives and electric current… Read more →

The temporary surface piping, valves and manifolds necessary to deliver a fluid treatment to the wellbore from the mixing and pumping equipment. Read more →

A fluid designed and prepared to resolve a specific wellbore or reservoir condition. Treatment fluids are typically prepared at the wellsite for a wide range of purposes, such as stimulation, isolation or control of… Read more →

Used synonymously with the term play to describe an area in which hydrocarbons occur, such as the Wilcox trend of the Gulf Coast. Read more →

Gas entrained in the drilling fluid during a pipe trip, which typically results in a significant increase in gas that is circulated to surface. This increase arises from a combination of two factors: lack of circulation… Read more →

A positive-displacementreciprocating pump that is configured with three plungers. Triplex pumps are the most common configuration of pump used in both drilling and well service operations. Pumps used in well service… Read more →

The act of pulling the drillstring out of the hole or replacing it in the hole. A pipe trip is usually done because the bit has dulled or has otherwise ceased to drill efficiently and must be replaced. Read more →

The minimum (negative) deflection of the seismic wavelet. Seismic interpreters commonly pick or track seismic data on paper sections along the trough of a wavelet rather than the solid-colored peak. With the advent of… Read more →

With reference to core analysis, the resistivity of a sample only partially filled with water. Called Rt, it is used in contrast to the resistivity of a sample completely filled with water, Ro. The water may be replaced… Read more →

The thickness of a bed or rock body after correcting for the dip of the bed or body and the deviation of the well that penetrates it. The values of true stratigraphic thickness in an area can be plotted and contours… Read more →

The vertical distance from a point in the well (usually the current or final depth) to a point at the surface, usually the elevation of the rotary kelly bushing (RKB). This is one of two primary depth measurements used… Read more →

The thickness of a bed or rock body measured vertically at a point. The values of true vertical thickness in an area can be plotted and contours drawn to create an isochore map. Read more →

Steps in seismic processing to compensate for attenuation, spherical divergence and other effects by adjusting the amplitude of the data. The goal of TAR is to get the data to a state where the reflector amplitudes… Read more →

An interface wave that occurs in cased wellbores when a Rayleigh wave encounters a wellbore and perturbs the fluid in the wellbore. The tube wave travels down the wellbore along the interface between the fluid in the… Read more →