珠江口盆地少井条件下井间CO_(2)气顶预测方法研究

Research on CO_(2) gas top prediction methods in the condition of Pearl River Mouth Basin with fewer wells

珠江口盆地EPA油田,储量占比大,其能否高效开发对于公司增储上产意义重大。该油田油气藏类型复杂,钻遇有纯油层、纯CO_(2)气层和带CO_(2)气顶的油层,但含油范围内仅1口钻井,未钻遇构造高点的油层不确定是否带气顶,由于温室气体CO_(2)的腐蚀性,CO_(2)气顶薄油藏开发将使工程设施投资大幅增加。为了研究清楚CO_(2)气顶分布,给油田储量评价和开发方案制定提供依据,减少开发不确定性,本次研究首次综合运用岩石颗粒溶蚀法、黏土矿物演化法、地饱压差法、圈闭充满度和盖层封堵法,探索了一套少井情况下CO_(2)气顶预测技术,从而指导储量精细评价和开发方案制定,为油田开发奠定了坚实的基础。后期钻探评价井进一步证实了该技术方法的可靠性,可推广应用到其他少井油田的气顶预测。

Pearl River Mouth Basin EPA oilfield has a large proportion of reserves.Whether it can be developed efficiently is of great significance for the company to increase reserves and production.The types of oil and gas reservoirs are complex.There are multiple gas cap reservoirs,gas reservoirs and oil reservoirs.Only one wells is drilled in the main oil area,most of the layers are not drilled to meet the structural high point.We are unable to determine if there are gas caps or not.The CO_(2) gas is greenhouse gas and it's corrosiveness will increase the project investment greatly.In order to study the existence of CO_(2) gas cap on the high point of structure,and provide basis for the reserve evaluation and the oilfield development plan,and finally reduce the uncertainty of oilfield development.The paper used the rock particle dissolution method,clay mineral evolution method,difference of formation pressure and saturation pressure,the filling degree of trapping and the cap rock blockage method to predict the distribution of CO_(2) cap.Finally,the paper explored a set of CO_(2) gas cap prediction technology under the condition of few well which can be applied to guide the precise evaluation of reserves and development plans,and also lay a solid foundation for the oilfield development.The later evaluation wells further confirmed the reliability of the technical method,which can be popularized and applied to other gas-cap oilfields with few wells.