松辽陆相湖盆河流-三角洲各种沉积砂体的油水运动特点

大庆油田是实施早期内部分层注水的一个多砂层油田.二十年来,发展了一套分层开采工艺技术,积累了大量的分层动态资料.通过开发实践,发现陆源砂岩油层的油水运动特点,很大程度上决定于沉积成因所控制的砂体特征.因此,通过对砂岩储油层进行逐层的细分沉积相研究,不仅可以加深认识和预测油层的原始地质特征,而且还可能预测和加深认识注水开发中的油水运动特点.这对合理制定开发措施,提高砂岩油田的注水开发效果,有着重大的现实意义.

CHARACTERISTICS OF OIL-WATER MOVEMENT IN FLUVIAL-DELTAIC SAND BODIES DEPOSITED IN CONTINENTAL LAKE BASIN

Based on studies of sedimentary fades of reservoirs in the Daqing oil field,delta complexec deposited along the Long axis of a continental lake basin,are classified into three depositional models depending on the differences of energy between the river and the lake.They are(1)bird-foot delta formed during rapid regressions(2)lobate-delta developed during slow regression,and(3)sheet delta formed during transgression.The main sand-bodies deposited under fluvial-deltaic environment in a lake basin include channel sand-bodies(point bax,abandoned channel sand); distributary channel sandstones(straight or meandering); delta front sand-bodies(river-mouth bar,sheet sand in the inner fringe and outer fringe),and inter-delta sheet sand-bodies.They are different from each other in geometry and internal texture.Therefore,they have different performances in oil-water movement during water-flooding.Generally speaking,the river-mouth bar yields the best results in development,followed by distributary channel sand and channel sand.Sheet sand stands last in the list.Sweeping efficiency and pattexn of water-flooding of the various types of sand bodies are discussed with more details.