东濮凹陷超压异常与次生孔隙

目的探讨东濮凹陷深层超压异常的形成原因和对储层的影响。方法利用实际资料，发现异常高压纵、横向分布特点，从宏观和微观两方面对其成因和对储层的作用进行分析。结果超压异常的形成与不均衡压实、孔隙流体增加、孔隙体积减小有关；超压异常控制成岩作用环境及孔隙的纵向演化，主要表现在高次生孔隙的发育和孔隙的分带性；次生孔隙的发育主要受微裂缝形成、生烃酸性环境溶蚀作用、热液循环溶蚀作用、热液交代作用和原生孔隙保存作用的影响。结论在异常超压控制下，东濮凹陷深层形成了次生孔隙发育带为主、次生孔隙递减带和致密带为辅的次生孔隙分布格局，次生孔隙带的广泛发育对扩大东濮凹陷深层勘探领域具有重要意义。

Overpressure and secondary pores in Dongpu Depression

Aim Overpressure is very prominent in Dongpu Depression, and in some area the geopressure is extra high. How does the abnormal pressure generated and its functions to reservoir should be discussed.Methods On the basis of RFT and production pressure data,the distribution of abnormal pressure were showed vertically and literally. The mechanism of abnormal pressure and its functions to reservoir were analyzed on macrography and microcosmic scales.Results The mechanism of abnormal pressure is related with disequilibrium compaction, increasing of fluid volume and decreasing of pores. Overpressure controls the diagenesis environment and pore evolution, which is showed in vertical change of pore and high secondary pores. There are five effects to contribute to secondary pores, microfissure, and corrosion in acid environment of hydrocarbon generation, corrosion of thermal cycle, hydrothermal metasomasis, preservation of primary pores.Conclusion Under overpressure, pores mainly develop in secondary pore interval and at the same time part of pores distribute in decreasing interval of secondary pores and tight interval. The secondary pores are very important for deep basin hydrocarbon exploration.