徐深气田火山岩气藏水平井开发优化设计技术

摘要

徐深气田属于深层大型低或特低渗透火山岩气藏,岩性、岩相横向变化快,有利相带延伸范围有限,气藏底部普遍发育水层;储层以Ⅱ、Ⅲ类为主,物性差,气井以压裂投产为主;现有地震技术难以准确预测有效储层分布特征和天然裂缝发育特征.针对火山岩气藏地质特征复杂和水平井开发设计难度大等特点,通过多年的水平井开发实践与攻关研究,形成了适合徐深气田火山岩气藏特征的水平井开发优化设计技术,并取得了明显的应用效果,为提高徐深气田火山岩气藏储量动用程度和整体开发效益提供了强有力的技术支撑,对同类气藏水平井设计具有指导作用.%Xushen Gasfield belongs to deep large-size low or ultra-low-permeability volcanic gas reservoirs, which is characterized by the fast lateral lithology and lithofacies changes, limited favorable facies-belt range and generally well-developed water layers in the bottom of gas reservoirs; the reservoirs are mainly composed of Type II and Type HI ones with poor physical properties, and moreover the gas wells are initially produced in the form of fracturing; the current seismic technologies are difficult to accurately predict the characteristics of the reservoir distribution and natural fracture development. In light of the complex geological properties of the volcanic gas reservoirs and the serious difficulty in horizontal well development design, the optimized design technique of the well suited for the properties is established through many-year development practice and deep study. The acquired apparent application effects have provided powerful technical support for increasing the developed reserves degree and entire development benefits of Xushen volcanic gasfield. And furthermore these achievements possess guidance and reference significances for the horizontal well design in such similar gas reservoirs.