The Rasearch Of Dynamic Analysis And Rational Injection-production Ratio Of Ansai Oilfield Wangjiawan Block

The WangJiaWan block of AnSai oilfield which located in the middle of ShanBei slope of Ordos basin is a oil fileld with a typical low permeability. Since developed from1994, it went through three periods which are natural depletion, injection test and full scale waterflood phase. With those development processes, the reservoir characteristics and oil-water move methods became much more complicatedly. All kinds of production problems exposed gradually, such as producing energy decreasing and water cut trend rising. As a particular important index of waterflood development, injection-production ratio has a close relation with the reservoir pressure, height of level, and water ratio. The research of the reasonable injection-production ratio is very important to the long-term production and the ultimate recovery improvement of the Chang2reservoir in this oilfield.This article based on the study of stratigraphic division and correlation, sedimentary facies, reservoir characteristic, geologic reserve calculation and so on. Then, find the problems presented in the production by analysing present develop situation, deliverability partition, producing energy, water content of WangJiaWan block. At last, rational injection-production ratio of this block has been decided by optimised certain methods.Research suggests:the Chang2reservoir of WangJiaWan block is structural-lithologic deposit, sand body has good communication, Chang212and Chang213are the main reservoir, arcose seizes major part of reservoir sandstone. Reservoir sensitivity present:weak-strong water sensitivity, no acid sensitivity, weak salt and velocity sensitivity, wettability performance for weak hydrophilic-hydrophilic, suitable for water injection development. The problems existing in the current development of this area are low producibility, high water cut and oil reservoir energy inequality. Combined with the reservoir characteristics and dynamic analysis, finally rational injection-production ratio decided by material balance method and waterflood characteristic method is1.1, this conclusion has a important meaning for WangJiaWan block.