Abstract
In times of increasing energy demand the need for more natural gas is greater than ever. To address this demand there are many drilling campaigns of coal seam gas (CSG) wells to supply the new liquefied natural gas (LNG) plants. Typically, within these wells progressive cavity pumps (PCP) are used to unload water to facilitate gas production. The produced water is then commonly processed by reverse osmosis (RO) to provide water suitable for re-use in other industries.
Previously PCPs were the only feasible pumping option, due to the presence of particulates, which is a relatively expensive deliquification method. Nalco has developed an alternative artificial lift method in the form of a liquid chemical foamer. This method offers cost efficient lift that will support initial liquid unloading as well as aid liquid management to maturation, enhancing lifetime production and lowering operating expense. In addition the technology offers secondary benefits for corrosion management, improving potential asset longevity.
The chemical has been demonstrated to perform in typical CSG brines and in the presence of coal fines, however the significant technology breakthrough is the compatibility with the RO membranes. Conventional foamer surfactants are incompatible and compromise safe, efficient unit operation. The laboratory and field data to demonstrate these claims is presented within.
To further enhance the technology offering a total deliquification approach has been developed, combining the chemical with a patented injection system. Appropriate steps have been taken to ensure the chemical is compatible with the injection system hardware and operating conditions, and most importantly benefits from the novel atomizer valve. In comparison to standard injection valves significant gains have been recorded in the field circa. 30%. The process of well selection, hardware installation, chemical treatment and monitoring is detailed within the paper.
