Month: July 2009

Prestack depth migration is a key seismic technology for improving oil discovery in global oil exploration activities that works especially well for complex geological structures such as subsalt layers, basement fractures and other high-velocity layers. Compared to conventional time migration image processing, which assumes that seismic waves are propagated in straight rays, PSDM is more expensive and time consuming but is more likely to precisely determine the structure of oil and gas reservoirs

An examination of reservoir fluids in a laboratory under various pressures, volumes, and temperatures to determine the characteristics and behavior of the fluid

One of three common methods to remove nitrogen from natural gas. The pressure swing adsorption process utilizes a carbon bed technology to separate the nitrogen from the hydrocarbons and can perform effectively even where there are large amounts of nitrogen in the feed stream. A particular advantage of the pressure swing adsorption process is its scalability. It can be used in small plants designed to handle 100,000 cubic feet of gas per day as well as plants processing volumes in the millions of cubic feet.

A pressure survey is conducted after the first year of production in a gas well and consequently annually. The survey is required to review the decreasing trend of the pressure in a gas reservoir in order to estimate the amount of gas that remains. Since the pressure in a reservoir decreases in a linear manner to the decrease volume (each 1% of gas removed should in principle cause a decrease of 1% in the reservoir pressure), it is a good instrument to gauge the amount of reserves remaining after a number of years of production. After 5 years if you have taken out 1/3 of the gas from a 15 year field the usual pressure will have dropped equally by 1/3 of the original pressure, so that after 5 years a competent operator would know how much gas he has left in his field. If you have an initial pressure of 2000 PSI and after 5 years you have 1500 PSI the operator should conclude that he has 15 years worth of gas left. The survey helps the operator to have a better understanding of the well performance

Pressure spike/excursion moving through the pipeline at sonic velocity, produced by a sudden change in velocity of the moving stream of oil that results from shutting down a pump station or pumping unit, closure of a valve or any other blockage of the moving stream.

A valve designed to open automatically to relieve pressure and keep it below a designated level.

Pressure: formation pressure increases with depth; pressure prediction plot is used to forecast pressure distribution along the well path; pore pressure is the pressure at which pore fluids leave the formation and influx into the well; fracture pressure is the pressure where the formation breaks down (the aim is to remain between these two former pressures); hydrostatic pressure is the pressure equivalent to the water column; over pressure is when the pressure is greater than that predicted for the depth (causes problems because of fluid influx); depleted zones are where the pressure is less than is should be for that depth (mainly caused by hydrocarbon production); pressure is usually managed using drilling mud