The Study On Exploitation Effect And Second Tertiary Combined Development Adjustment Of Sub-mainlayers And Tertiary Mainlayers In Sazhong Area

Sazhong development area in Daqing oilfield entered a new development stage of extra high water-cut, high cost and high development difficulty.Polymer flooding of mainlayers have accessed epilog, tertiary recovery have turn to sub-mainlayers, water drive geological reserves are decreasing. Waterflooding exploitation potential of Tertiary infill development decrease after primary and secondary well pattern thickening, the capability that increase recoverable reserves and output decline, thus an inadequate oil reserve as well as a lower productivity prospect is seen,economic benefit is bad.Because of these, Waterflooding is confronted with complexion that R/P ratio is unbalance seriously, natural decline rate is biger and biger, production capacity reduces continuously. Under this condition, Sazhong development area raise water drive development test which advancingly study on second tertiary combined of sub-mainlayers and tertiary mainlayers in the period of the eleventh five year plan, so as to ensure a desirable production rate and a sustainable oiIfield development.The sub-mainlayers and tertiary mainlayers in Sazhong development area have over hundred sedimentation unit.The aggregate thickness is big,and sandstone thickness is more than sixty meters. The reserves is big, and occupies seventy point two of total reserves. The oil layer anisotropism is serious, and on longitudinal alternately distributes in the plane, therefore, independently they are mined with difficulty in the development. After many times water drive infill adjustment, has formed the complexion that is multi- wraps well pattern and multi- wraps formation mutually consummate injection/production relations to mine the sub- mainlayers and tertiary mainlayers. In order to alleviate the plane and intrabed contradiction in tertiary phase, and uttermostly enhance oil recovery factor, the sub-mainlayers and tertiary mainlayers still needed to subdivide the mining object and the formation, uses the well pattern and spacing which adapted with it . Therefore, this topic is for the purpose of utilizing compr- ehensively reservoir engineering methods and the fine numerical simulation method to thoro ughly evaluate and research the sub-mainlayers and tertiary mainlayers'water drive develop- ment effect and remaining oil's pattern. Respectively and independently deploying a set of well patterns, synchronically drilling and water driving, coordinating and consummating injection/production relations from the plane and longitudinal. Integrally reseaching the second tertiary combined development adjustment well pattern deploy, test oil layers combination optimization schemes,polymer flooding's logical join time and deliverability join relation , optimize a set of optimal combination development type that is adapted with sub-mainlayers and tertiary mainlayers by utilizing the numerical simulation (streamline simulation ) technology and field experiment. The optimal appraisal results are reasonable and reliable, conform to the field reality.These research results provide the scientific theory foundation for reasonably dugging remaining oil of sub-mainlayers and tertiary mainlayers and enhancing the crude oil recovery factor.