An electric submersible pump (ESP) is an artificial-lift system that adds energy to the produced fluid downhole. You may also see the name written as electrical submersible pump. A power cable feeds an electric motor, the motor turns a shaft, and a series of centrifugal stages raises the fluid pressure between the pump intake and …
Gas lift in oil wells uses compressed gas to help reservoir fluids reach the surface. In a conventional tubing-flow completion, gas travels down the space between casing and tubing, crosses into the tubing through a valve, and returns with the produced fluids. The entry point is therefore in the wellbore. Reservoir pressure maintenance, in contrast, …
Formation damage is a reduction in the ability of reservoir rock near a well to transmit the fluid being produced or injected. It can result from blocked pore throats, changes in sensitive minerals, or changes in fluid saturation and relative permeability. Consequently, a damaged interval may need more pressure difference to deliver the same flow …
Tubing movement calculations estimate how much a completion string changes its end-to-end length when pressure, temperature or mechanical loading changes. For tubing that can slide through a packer seal bore, the result helps determine the required movement range. For anchored tubing, the same imposed changes can generate additional tubing and packer loads. Establishing the actual …
A landing nipple is a completion-tubing component with a machined locking profile and sealbore for a compatible lock mandrel and downhole device. Selective systems allow a chosen landing location; no-go systems use a locating shoulder. The nipple provides the receptacle, but the installed plug, valve or instrument assembly determines the function. This guide explains landing-nipple …
Guns normally run on wireline or tubing can also be run using coiled tubing allowing through tubing perforating to be carried out in horizontal wells. An electrical wireline can be installed inside the coiled tubing to allow depth correlation with casing collars or a gamma ray and the use of electrically initiated detonators. Here, we …
Thru tubing perforating guns is a technique dating from the 1950s. Using a seal around the cable at the surface allows perforating of hydrocarbon wells while there is pressure at the surface. This enables perforation of the well without excessive hydrostatic pressure caused by drilling or workover fluids. Please note that this type is different …
Hollow carrier casing guns are the direct descendants of the original perforating guns that have been in use since the 1930s. These guns are available in diameters from 86 mm (3 3/8″) to 184 mm (7 1/4″). Furthermore, they can contain up to 46 shots per meter (14 shots per foot). Large-diameter steel carrier casing …
In 1932, the first bullet perforation gun was developed. This gun created a flow path from the formation into the casing by firing a projectile (bullet) through the cement and casing. It was known for providing a very uniform hole in the casing. However, as well depths required higher strength casing, it became less effective. …
Wireline conveyed perforating is an established, proven technique of unquestionable reliability. It is often the cheapest perforating method technique and more reliable than the alternatives. The consequences of a misfire are minimized by the ease with which guns can be pulled from the hole and re-run. Due to the gun’s weight, only a limited interval …