Fine Numerical Simulation Research Of Secondary Development Adjustment In Qi3-17-5Block

Lianhua oil layer of Qi3-17-5block is located in the south section of the western slopeof Western depression in Liaohe Basin, with the geological reserves of385.618×104t. Afternearly30years of development, it has experienced four development phases, which are theproduction rose, production decline, infilling adjustment and low efficiency phase. By the endof2009, oil recovery degree of Lianhua oil layer is12.569%, water content67.079%and oilproduction rate only0.029%. At present, problems that difficult water injection, low oilproduction rate and recovery degree are existed in the reservoir. This paper mainly uses thenumerical simulation method to research the remaining oil distribution rules in the reservoir,and evaluates the development effects by using reservoir engineering methods so as tolooking for the potential tapping direction of remaining oil and a new development way forthe secondary development of Lianhua oil layer.Result of the natural reservoir energy classification of Lianhua oil layer shows that, thereis a certain natural energy in this oil reservoir. But due to the strong plane heterogeneity, highoriginal formation pressure, so many faults and poor interwell connections, water injection inthis block is more difficult and the utilization rate of injected water is much lower. Theultimate oil recovery rate predicted by production decline method is about12.954%while theoil recovery rate of water flooding predicted by empirical formula method is about16.932%.Therefore, in the case of depleted natural energy, water flooding development in this blockhas certain potential. By evaluating the development effect of Lianhua oil layer, bad changerules of water cut, low measure efficiency, low connectivity coefficient under large wellspacing, low water flooding control degree and reserves producing degree indicate that theoverall development effect is unsatisfactory. Based on the Petrel three-demensional finegeological model, numerical simulation software Eclipse is used to research the remaining oildistribution rules in Lianhua oil layer. Remaining oil is enrichment in the areas with imperfectinjection-production relationship and low well network control degree or in the edge orcorner of faults. By comparing the three programs for the secondary development, at the baseof full use of the original well network, infilling a new water injection well, adjusting aproduction well into the water injection well, shooting open upper layers for two oil wells andfilling other layers for another five production wells could guarantee the oilfield obtainingbetter economic benefits as well as high oil production rates. Ten years later, as the optimizedprogram predicting, the stage recovery degree will be3.108%and comprehensive water cut isreduced to46.88%.The contents and results of this paper clarify the underground oil and water distributionrules of Lianhua oil layer, and the optimized development programs has an important guidingsignificance of the selection on its secondary development mode.