Month: July 2009

Gas that is left over after fuel is burned and which is disposed of through a pipe or stack to the outer air

Pressure at the wellhead with well flowing

A well that produces oil or gas by its own reservoir pressure rather than by use of artificial means (such as pumps).

In time the flowing tubing pressure of a gas well may decline and further compression may be needed

The pressure of the flowing well measured at the intake point in the borehole.

The ability to monitor bottomhole flowing pressure in pumping oil wells provides important information regarding both reservoir and artificial lift performance. Converting surface pressure measurements to bottomhole is currently accomplished by locating the fluid level in the annulus using a sonic device and then applying a correlation to estimate the density of the gas-cut liquid column above the perforations

An operation on a well designed to demonstrate the existence of moveable petroleum in a reservoir by establishing flow to the surface and/or to provide an indication of the potential productivity of that reservoir. Some flow tests, such as drill stem tests (DST) are performed in the open hole. A DST is used to obtain reservoir fluid samples, static bottomhole pressure measurements, indications of productivity and short-term flow and pressure buildup tests to estimate permeability and damage extent. DSTs are performed in the open hole. Other flow tests, such as single-point tests and multi-point tests, are performed after the well has been cased. Single-point tests typically involve a measurement or estimate of initial or average reservoir pressure and a flow rate and flowing bottomhole pressure measurement. Multi-point tests are used to establish gas well deliverability and absolute open flow potential. When you test a small amount of gas or oil over a period of days the pressure it is at will often decline indicating limited amounts of oil or gas present. If a performance modeling indicates that a well can be ultimately completed to achieve a high production rate (e.g. production rate of over 150 Mmcf/d. as reported by Noble Energy regarding Tamar), it is an indication that the pressure in the well was fine, although eventually it is long term testing over several months rather than days that proves an accurate state of affairs