The basic West Texas separator was developed in the 1950s to drill the Permian Red Beds in West Texas and is still the ''gold standard'' atmospheric separator. Drilling fluid is taken from the bottom of the far end of the tank, and during connections oil is pumped to a shale tank. The open tank then acts as a separator, with the gas escaping to the atmosphere, the oil and drilling fluid separating, and the solids settling out on the bottom.
The drilling-fluid/gas/oil mixture is sent directly to an open tank, normally a frac tank, with the flowline in line with the long axis of the tank. They are easy to set up and inexpensive to operate.Ī simplified tank separator system is used with some workover and small drilling rigs. Mud tank separators, often used in the southern end of the Austin Chalk trend in Texas, allow the limited hydrocarbon vapor to escape and settle many of the solids in the bottom of the skimmer tanks. The drilling fluid is taken from the bottom and sent to the solids-control system.
In the tank sections, the oil is successively skimmed off with siphons or skimmers, and concentrated oil is pumped to a shale tank.
TANK BUSTER BUILDS FREE
The drilling-fluid mixture may be first passed through a West Texas type of separator (see the section to follow) to remove the free gas, and then it is sent to the first of several mud tanks. Several extra mud tanks are commonly used when there is significant amount of free oil to be separated from a water-base drilling fluid. Oil/water separation can then be carried out with a simple siphon. With gravity separation, gas rises and escapes the oil separates from the drilling fluid and rises to the top of the tank. The simplest atmospheric separator is a mud tank that uses gravity separation. The purpose of a separator is to separate free gas or mixed gas and oil from the drilling fluid and convey the gas or oil to a flare or holding tank. The offshore gas buster is closed and usually has a U tube on the line to the shaker to build backpressure and force gas to the discharge line.ĩ.7 SEPARATORS 9.7.1 Atmospheric Separators The offshore version of the gas buster uses an 11-inch casing up to 20 feet tall ahead of the shale shaker. In heavy mud and with higher than normal initial gel strength, the baffle system may cause some entrainment of the gas, which appears as gas cutting. This system is unbalanced, and the pipe needs to be restrained. Intake balances the force of the drilling fluid and expanding gas so that the gas-buster tank does not need heavy bracing.Īnother version of the pipe gas buster uses the same casing size as the standard gas buster but directs the mud and gas mixture onto a blast plate or "baffle," which breaks up the flow pattern and separates gas and drilling fluid. The tangential intake is used on many land rigs where the gas buster is installed in the possum belly (back tank) of the shaker.
A pipe on the top carries the gas away, and the bottom of the casing is open to the shale tank on the shaker. The mud entering the inlet spins, and the centrifugal force allows the gas to go to the center and out while the mud goes to the sides and down. An inlet, tangent to the side but tilted up about 5°, is welded into a 6-ft (2-m) length of casing about one third of the distance from the bottom. (Often the gas is starting to break free in the flowline.) A problem with the basic gas buster is that the heavier gases will not rise and be dissipated in the air but settle around the rig.Īn old-fashioned but effective gas buster is made from a piece of 9- or 11-inch (228.6- or 279.4-mm) casing (Figure 9.1). A gas buster works well in fluid with large bubbles of free gas. The purpose of a gas buster is to remove gas mixed with the drilling fluid before the drilling fluid goes over the shale shaker.
0 kommentar(er)
