底水油藏水平井分段开采研究与设计——以大港油田庄海8馆陶组为例

Research and Design on the Segregated Production with Horizontal Well in Bottom Water Reservoir——An Example of Guantao Formations in Zhuanghai 8 Block in Dagang Oil Field

目前国内绝大多数底水油藏采出程度较低,开发效果不理想,如何进一步提高该类油藏的采收率,是油藏工程技术人员不断的追求与奋斗的目标。以大港埕海油田庄海8馆陶组底水油藏为例,通过对经验与教训的分析,开展了非均质底水油藏中不规则井身轨迹的水平段压降、流量等沿程分布规律的研究,定量描述底水油藏水平井水平段内部流量及压力的分布,明确底水锥进规律。以此为基础进行水平井优化设计,结合储层分布、水平井完钻轨迹、油藏波及动用范围,提出水平井防砂完井分段采油技术方式,实现长水平段内生产压差有效控制,实现了水平段内均衡的采油。理论与实际生产证明,水平井分段开采是不分段开采产量的2倍以上。底水油藏水平井分段开采技术的研究与试验,起到了控水增油的效果,为国内外此类油藏水平井改善开发效果探索了新的途径。

At present, the oil recovery percent is low in most of the bottom water reservoirs, and the oil production results are always not satisfactory. How to enhance the oil recovery of such reservoirs, this is the pursuit and goal for all reservoir engineers. With the bottom water reservoir in Neogene Guantao formations of Zhuanghai 8 block in Dagang oil field as an example, through analysis of the experiences and developemt lessons in this kind of bottom water reservoirs, we have conducted the research on the pressure drop and flow regularity along the way of irregular wellbore trajectory in horizontal segment in heterogeneous bottom water reservoir, and quantitative analysis about the pressure and flow regularity within horizontal segment in horizontal well, and made clear about bot- tom water coning regularity. On the basis of the study results, the design of horizontal well has been optimized. In addition, combin- ing with the study about reservoir distribution, the trajectory of the horizontal well, water flooding sweep and producing region of reservoirs, the technique of sand control completion and segmented exploitation in horizontal well is proposed. This technique is very effective in controlling producing pressure drop within long horizontal segment, and the equilibrium oil recovery in horizontal seg- ment has been achieved with this technique. It has been proved through the actual production that the production rate has increased by two times or more with segmented exploitation method compared with not using this method. The water cut has been controlled and oil production has increased by using this technique, which provides a new method to improve oil development results in horizontal well for such reservoirs at home and abroad.