The Feasibility Study Of Natural Gas Drive Enhanced Oil Recovery Of Dongshengbu Buried Hill Reservoir

In the entire research process of the thesis, we survey the tectonic and the developmentfeatures of Dongshengbu Buried Hill in detail. Overall, Dongshengbu Buried Hill Reservoirwhich is a fractured massive reservoir with bottom water has the characters of layer structureand high pour-point crude. Entering the preparation stage since1982, it experiences the stageof testing and producing test、productivity construction、water injection and stable yields、production decline. As the flood effectiveness unsatisfied, from1994, the Reservoir stopinjecting water, for improving the development effect of middle and final stages ofDongshengbu Buried Hill Reservoir, According to the current situation of water floodingdevelopment effect is unsatisfied, Gas injection as a methods of keep reservoir pressure andimprove the development effect and oil recovery is proposed.The thesis is based on the theory of EOR by gas injection, through a series of laboratoryexperiment and application of reservoir numerical simulation technology, demonstrating thefeasibility study of gas injection of dongshengbu buried hill reservoir. The completedresearch work and achievements are as follows: Summarizing the results and experiences ofthe hydrocarbon gas injection technology at home and abroad. Making an in-depth analysis ofthe miscible and immiscible displacement mechanism; Summarizing the effect factors of gasinjection from both static and dynamic parameters. Through empirical formula and a finetube experiments to determine the minimum miscible pressure of gas drive of dongshengburied hill reservoir is31.6MPa; Carrying out long core gas injection displacementexperiment, Studied the impact of permeability、injection pressure、gas injection rate,injection timing and other parameters on the effect of displacing oil by gas. Establishingdual-permeability geologic model and production performance model of dongsheng buriedhill reservoir, completed production history matching of the early gas injection, mastering thedistributing law of the current remaining oil, through the filtered well group to forecast thenatural gas drive, The results indicated that the prediction effect of gas injection is better thanwater flooding, the recovery degree after gas injection is4.3%higher than water flooding; Inthe same condition, the best effect of gas injection rate is0.15PV/a; Through optimized gaswater alternating injection plan, which solution is gas water ratio2:1, the shorter the alternatecycle, the development effect is better.