Study On Water Injection Development Technology Of M2 Block In XM Oilfield

The Fuyang reservoir of XM oilfield is typical low porosity, low permeability and strong heterogeneity. In the process of water injection, some apparent characters were present, such as water injection is difficult for water wells, the injection pressure is high, the oil wells are not well efficient by water injection and the fluid production is low. This paper is mainly on the problems in the water injection process of this reservoir, and choose the M2block as the representative block, through deepen geology knowledge,the dynamic data analysis of the reservoir production, the combine the reservoir engineering theory and use reservoir numerical simulation technology to study the effective waterflood technology.By the evaluation of the current waterflood development effect, clearly have a knowledge of the difficult waterflood problems in the development process. By the analyze the main factors that affect the water injection development effect, identify these effects in the development process. Furthermore, make an effective waterflood technical countermeasure. For building effective displacement pressure system, according to the enrichment conditions of the current remaining oil, combine the results of the reservoir engineering research to design the flowing adjustment measures:well pattern infilling, injection-production ratio preferred, fill holes and fill layers etc. By design9sets of adjustment measures, then predict and prefer these measures, and the analysis results show that the flowing conclusions.(1)The reservoir stratum has stress sensitivity and threshold pressure gradient, which cause the water injection is difficult, so the reservoir pressure should be reasonable. Through the calculation we can know the reasonable formation pressure of M2block id14.2MPa, the reasonable bottomhole flowing pressure of production well is2.77MPa, and the max bottomhole flowing pressure of injection well is21.78MPa, The biggest reasonable production differential pressure is11.43MPa.(2)The block is strong water sensitivity and salt sensitivity, so the quality requirement of the injected water is high. Because of each block exists serious reservoir fouling phenomenon, which has a great damage to formation, it should take measures such as deep acidification, near wellbore plugging.(3)For the starting pressure gradient phenomenon of the blocks is high, should be use the small well space method to development, which can establish effective displacement pressure system. Besides, the limit injection-production well space is140m.(4)By reservoir numerical simulation, predict the various adjustment measures, and the results show that, it can establish an effective displacement pressure system by well pattern infilling, improve the waterflood development and the best injection-production ratio of the infilling adjustment well pattern is1.27. To enhance the oil recovery and keep the production is stable of the oilfield, it can take the flowing measures:infilling well pattern of remaining oil enrichment region, fill holes and fill layers, enhance liquid production etc.