超低渗砂岩油藏开发中存在问题及综合治理措施——以华庆油田元427井区长9油藏为例

Problems in the Development of Ultra-low Permeability Sandstone Reservoirs and Comprehensive Measures——Case Study of Chang9 Reservoir of Yuan427 Well Block in Huaqing Oilfield

超低渗砂岩油藏中,高含水期的综合治理一直是国内外研究的一个难点。华庆油田元427井区平面上地层压力分布不均,纵向上吸水不均突出,东部高含水饱和度区局部油井见地层水。通过合理优化长9油藏注水技术政策,降低递减速度;通过开展注聚合物微球整体调驱,扩大注入水波及范围,改善水驱效果;通过摸排普查潜力层、潜力层补孔及井筒清防蜡、防垢、防偏磨、参数优化等综合治理措施使区块达到高效开发的目的,同时也为同类油藏的合理开发提供借鉴。长9油藏期通过注水技术政策调整,优化调整32井次,使区块阶段递减由调整前的46.7%降至7.2%;通过开展整体微球调驱,注水压力由13.0MPa上升至13.5MPa,水驱动用程度由69.6%上升至71.6%;通过实施井筒综合治理,实施参数优化23井次,平均泵效由19.0%上升至28.4%,油井生产时率提升10%。

Comprehensive management in high water cut period is a difficulty in the research of ultra-low permeability sandstone reservoirs at home and abroad.In Yuan427 well block in Huaqing Oilfield, formation pressure distributes unevenly on the plane, obvious uneven water absorption on the vertical, and formation water breakthrough appears in partial oil wells in high-water saturation area in the east part.Technical policy of water flooding in Chang9 reservoir was optimized to reduce the rate of decline;overall profile control and oil displacement through the injection of polymer microspheres were done to expand the swept area of injected water and then improve the water flooding effect;potential layer was surveyed and reperforated, anti-wax, antiscaling, anti -biasing of the wellbore, parameter optimization and other comprehensive measures make the efficient development of the block, and also provide reference for the rational development of similar oil reservoirs. Through the adjustment of water flooding technical policy in the Chang9 reservoir, 32 well -times were optimized and adjusted, and stage decline of the block reduced from 46.7% before adjustment to 7.2%.After the overall microsphere flooding was carried out, the water injection pressure increased from 13.0MPa to 13.5MPa, produced degree of water flooding increased from 69.6% to 71.6%.Through the implementation of comprehensive wellbore treatment, the parameters were optimized for 23 well-times, the average pump efficiency increased from 19.0% to 28.4%, and the oil well production rate increased by 10%.