Research and application of a new type of foam drainage agent for resistance to condensate oil

Aiming at the poor application effect of foaming agent in gas well with high content of condensate oil, using ampholytic surfactant as the main agent, introducing pro oil anionic surfactant on its side chain, adding a kind of self made cationic surface active agent after full reaction, a new type of foaming agent with good oil resistance has been produced.The laboratory performance of foaming agent was tested according to GB/T 13173.6-2000 Determination of foaming power of detergent, SY/T 5761-1995 Foaming agent for gas drainage CT5-2 and SY/T 6465-2000 Evaluation method of foaming agent for drainaging gas recovery.Under the conditions of 60 ℃ and condensate oil content of 30%, its foaming height and liquid carrying rate are as high as 105 mm and 62%, and it can be adapted to the temperature of 120 ℃, the mineralization degree of 250 g/L, methanol content of 30%.Four wells tests(10%~25% condensate oil content) in Sulige gas field were carried out, and the average pressure difference for oil and casing reduced 2.21 MPa, and gas production increased 0.45×10⁴ m³/d, drainage gas recovery effect was obviously.