The Research Of Different Foam Drainage Gas Recovery Optimization Technology In Jingbian Gas Field

Jingbian Gasfield is a low pressure and low permeability gas field,The block of gas wells have existed different levels of water production.In recent years,The oil field has carried out various research methods of drainage and gas production,Especially the popularization and application of foam drainage Gas Production,Gasfield achieved a better effect aboue drainage.But with the decreasing formation pressure,increasing number of producing Wells and formation water quality changing,it result a great difference in the effect of foam drainage.It is urgent to carry out the research on the different foam drainage gas recovery optimization technology according to the conditions of water and gas wells,the characteristics of water quality and the performance of foam drainage.Based on the investigation and analysis of Jingbian gas field development,Cause of water production and Foam drainage effect,the composition of water produced by different gas wells was analyzed synthetically Based on the combination of chemical volume method and instrumental analysis,And the advantages and disadvantages of various foam performance evaluation methods,the scope of application were analyzed and studied,At the same time,the performance evaluation method of foam drainage was carried out,Finally,bubble drainage was evaluated by the new method,The influence factors such as condensate oil,methanol and mineralization degree on the performance of foam drainage were studied in detail.To determine the different types of Producing gas wells for the different types of foam,the amount of foam drainage and foam drainage technology.Through the study above,the conclusions were as follows:(1)The advantages of using the standard static(Ross-Miles method)and dynamic(SY/T5761-1995?drainage gas recovery foaming agent CT5-2?)for Evaluation of the performance of foam are Simple and fast,But the disadvantage is that the evaluation of a single,one-sided,can not be associated with each other,The improved evaluation method can systematically evaluate the various properties of the foam;(2)By measuring the water content of the foam with time and the amount of foam with the flow rate changes can reflect the performance of foam;(3)The key factors that affect the performance of foam drainage are mineralization,oil and methanol so on;(4)The salt tolerance of the foam: 1#<200g/L;2#<100g/L;3#<20g/L;4#<100g/L;5#<50g/L;(5)The oil resistance of the foam: 1#<10%;2#<2.5%;3#<2.5%;4#<5%;5#<2.5%;(6)The methanol resistance of the foam1#<20%;2#<20%;3#<10%;4#<30%;5#<30%;(7)The classification of gas wells is divided into three categories(>100g/L)?Medium(<100g/L ?>50g/L)?(<50g/L)according to the total mineralization degree of water quality,Each category is divided into two categories High(>2.5%?<10%)and Low(?2.5%)according to the condensate oil content.(8)Low salinity and low condensate oil gas wells select 3#and5#,Low salinity and high condensate oil gas wells select 1#and4#,Medium salinity and low condensate oil gas wells select 2#,Medium salinity and high condensate oil gas wells select 4#,high salinity and high(low)condensate oil gas wells select 1#;(9)According to the gas well condition,Select the concentration,mode and cycle of the concentration of the agent to optimize the foam drainage technology of different gas wells in Jingbian gas field.