Gas well dewatering
Water present in a gas well generates pressure that lowers the gas productivity of the well. In this case, an Artificial Lift System is required to dewater the well and free up the trapped gas. PCM can help you resolving these challenges.
Gas well dewatering challenges
Coal Bed Methane (CBM) or Coal Seam Gas (GSG) is a gas recovered from coals seams. Water present in the seam prevents the gas from flowing. Removing the water depressurizes the seam and releases the gas. The technical challenge is how to dewater the well and dispose of the water as economically as possible. CBM is produced around the world and large developments are in progress.
Any Artificial Lift System used for CBM/CSG dewatering has to cope with fine particles of coal in the water. These particles can affect system performance, and the PCP is well adapted to pumping water with particulate content.
After the high flow rate present during the first dewatering phase, the water production decreases. The pumping system must be able to accommodate the various flow rates.
When gas is present in the water, the challenge is to keep the pump running and not endanger the run life.
If PCP is installed below perforations the gas separation is done naturally and free gas at PCP suction is reduced. However the PCP will handle important amount of solids and this could highly impact the run life.
If PCP is installed above perforation, the abrasion will be reduced but important free gas rate need to be supported by the Artificial lift method.
This can be achieved by using dedicated multiphase PCP PCM MoineauTM HR.
Also, corrosion is always a challenge. Compatibility tests with corrosion inhibiting chemicals must be performed in order to avoid damage to the pump or components.
Why choose PCM for the gas well dewatering?
A multiphase fluid is a mixture of oil, water, gas and often some solid particles. Fluid characteristics (densities, viscosities and mixture composition), flow (pressure and temperature) and piping and well architecture determine the flow pattern, which in turn defines the multiphase flow behavior.
In oil & gas activities, multiphase conditions are omnipresent -- from the reservoir through the well and up to processing -- and must be taken into account when designing artificial lift systems.
PCM has perfected a patented self-pressure regulation technology called HRPCP (Hydraulically Regulated PCP) that allows PCPs to be used for multiphase pumping. It is available on PCM Moineau™ HR systems for artificial lift and PCM surface transfer pumps for surface transfer.