塔河9区油气层合采分层储量计算方法

Method for Calculating Zonal Reserves in Gas and Oil Reservoir Commingled Production of Block 9 in Tahe Oilfield

针对塔河9区奥陶系碳酸盐岩储层中部分井凝析气藏与油层合采时,生产气油比变化大、分层产量计算困难、单井控制储量及生产制度难以确定等问题,首先通过生产数据概述了塔河9区油气藏的生产动态特征,通过物理实验分别对油层与气层样品的组分和PVT物性进行了检测,根据流体的组分和PVT物性判定了储层类型;再利用油、气PVT试验数据与产出油密度,建立了合采井中凝析气层产量与油层产量的计算模型;最后,利用模型获取了油层与凝析气层的动态产量数据,并利用Fetkovich产量递减特征曲线方法和Arps方法分析了油层与凝析气层的动态储量。结果表明,塔河9区油层与气层不属于同一个流体系统,油层属于挥发性油藏,气层属于凝析气藏;所建立的模型能实现合采井中气层与油层分层产量的计算,TKX井油层产油量占总产油量的73.91%和总产气量的6.55%,气层产量占总油量的26.09%和总产气量的93.45%;Fetkovich方法和Arps方法计算的储量差距较小,Fetkovich方法计算储量可信度较高。研究结果对塔河9区奥陶系油气藏开发方案的制定有一定借鉴意义。

In the development of Ordovician carbonate reservoir in Block 9of Tahe Oilfield,there exist the problems of great changes of produced gas-oil ratio,difficult to calculate zonal production rate and the reserves control in single well and as well as hard to determine the production system,the dynamic production characteristics in Block 9are described by using production data,the component and PVT properties of oil and gas samples of the reservoir are tested separately,based on the fluid composition and PVT property,the reservoir type is identified.The PVT experimental data and the produced oil density are used to establish the commingled producing well calculation model of gas production in condensate gas reservoir and oil production in reservoir.Finally the dynamic production data in oil and condensate gas reservoirs are obtained according to the model,and the Fetkovich production decline curve method and Arps method are used to analyze the dynamic reserves in the oil and gas reservoirs.Result shows the oil and gas reservoirs in Block 9are not of the same fluid system,the oil layer is the volatile reservoir and the gas layer is the condensate gas reservoir.The established model can be used to calculate production of oil and gas commingled production,the oil production in Well TKX accounts for73.91% of oil production and 6.55% of gas production in the total production.The production of gas layer accounts for26.09% of the total oil production and 93.45% of the total gas production rate.There exists less difference of the reserves calculation between Fetkovich and Arps Methods,so the reserves calculation by Fetkovich Method is high reliability.The research results have certain significance for establishing the development scheme.