泌阳凹陷复杂断块群油藏特征及勘探技术

泌阳凹陷北部斜坡具有优越的油气富集条件。断裂系统、鼻状构造产状、砂体展布及三者的配置关系控制着斜坡带油气藏的类型和分布,西部古城油田以断鼻油藏为主,东部以断块、断层+岩性油藏为主。断层的形成时期晚于油气大规模运移期,各油田纵向上含油层位跨度大,主力油层分布集中,不同断块主力含油层位一致;从南向北油层埋藏深度逐渐变浅,原油性质相应变差;油层厚度薄,多数以中薄层为主;单个断鼻、断块含油带窄,低部位迅速变为水层,并具有多套独立的油水系统。准确落实断裂系统及其空间展布是勘探成败的关键。迅速发展的三维地震勘探、定向井钻探、井筒及油层保护等配套技术系列的应用,提高了复杂断鼻、断块群油气藏的勘探效益。

Features of the Complex Fault Block Reservoirs in Biyang Depression and Exploration Techniques

Favorite conditions for oil enrichment exist in the northern slope zone of Biyang depression.Reservoir types and distribution are under the control of fault systems,occurrence of structure nose,sandbody distribution and the relationship between the above three.In the west,fault nose is the main reservoir type in Gucheng oilfield,while in the east,there exist mainly fault block,fault&lithologic reservoirs.Faults formed after large-scale mi-gration of hydrocarbon and the vertical span of oil-bear-ing horizons are large in each oilfield with the major oil layers crowded together and consistent with each other in different fault blocks;from south to north,buried depth of oil layers gets shallower and crude oil properties poor-er;oil layers are thin and mostly are medium to thin layers;oil-bearing zones in a single fault nose or fault block are narrow and there exist several separate oil and water systems.The key to exploration is accurately locat-ing fracture system s and the distribution in space.Appli-cation of the rapidly developing technologies such as3-D seismic exploration,directional drilling and protection of wellbore and oil -bearing layers can enlarge benefits of exploration of complex fault noses and blocks.