Research On Deep Control Technology Of High Temperature And High Salinity Reservoirs

L oilfield is a super deep water drive, multi-layer sandstone oilfield.After water injection development for a long time, L2TI reservoir has turned into high water cut stage, the problem of strong heterogeneity and water channeling become more serious. L2TI reservoir needs effective water control technology to improve the water flooding development efficiency.L oilfield is characterized with well spacing greater than 500 m, well depth larger than 4700 m,formation temperature higher than 120? formation water salinity high up 160000-200000mg/L and the content of calcium and magnesium ions high up to 11550 mg/L and 1370 mg/L. In order to increase oil recovery, several matching technologys should be studied more carefully,such as water channel identification technology,deep profile control and displacement technology.To find the effective ways to improve L oilfield water flooding development efficiency, a deep profile control and displacement technology for high temperature and high salinity oil reservoir is developed.Specific research results are as follows:(1)The dimensionless pressure drop curve method and dimensionless chart comparison method are used for water channel advantage evaluation of L2TI reservoir. The distribution of water injection dominant channel in L2TI oil group was obtained.(2)The temperature resistance and salt resistance of microspheres, gel L-1 and gel L-2 were evaluated in laboratory. The profile control and displacement agent Suit L2TI high temperature and high salt reservoir was selected:The adaptability of microspheres and gel L-2 was good, and the formula of gel L-1 was further optimized.(3)Based on the optimization of profile control and displacement parameters, the design of profile control flooding scheme for L2TI reservoir is completed:The microsphere is a plug of the profile control and displacement, and the gel L-2 is a sealing part. Numerical simulation predicts that the effective period is 2 years, the increasing oil amount is 3.85 million tons,the oil recovery can be increased by 1.03%.(4)After the implementation of the project, the oil well and water well have a significant effect:The injection pressure of 4 water injection wells was obviously increased, the apparent water absorption index was decreased, the pressure index was improved, and the suction profile was improved. Well test interpretation data show that the permeability of water injection wells decreased significantly after flooding. The corresponding oil wells are all effective, and the effect of increasing oil and precipitation is obvious. The daily production of crude oil rose from 50.7 tons to 83.6 tons, up 32.9 tons; the water cut decreased from 95.3% to 93.3%, a decline of 2%, the water cut rising speed slowed down. To March 31,2016, taking into account the natural decline rate, the experimentation area has increased crude oil production 1.21 million tons.The successful implementation of the pilot test of the deep reservoir flooding in L2TI oil reservoir, shows that it is feasible to apply deep profile control technology in high temperature and high salinity reservoir. This successful experience will provide a positive guidance for the application of enhanced oil recovery technology in the development of water flooding in Tarim Oilfield.