Water Drive Oil Field Development Effects Evaluation Method

The practice of oil field development indicated that the water flooding development can achieve ultimate recovery. No matter in our country or in abroad, there are some reservoirs which have obvious natural edge water energy. When exploiting these kinds of reservoirs, we could using its natural energy sufficiently and reasonably to realize the natural flooding development. Because of its geology and displacing agent behavior, the water-free recovery and ultimate recovery will be high. But by reason of formation's anisotropy and the deficiency of natural water energy, for the sake of improving displacing efficiency, sustaining formation energy and enhancing the ultimate recovery, most of reservoir should supplement the artificial water injection. For the moment there almost have no special and systematical achievement reports on how to evaluate the effect of flooding development. This paper expounded how to evaluate the flooding development effect systematically on the facet of traditional petroleum reservoir method, the theory of fuzzy mathematics and numerical simulation, etc. Take the Cainan Sangonghe reservoir in Xinjiang as an example, we evaluated the development effect qualitatively and quantitatively. Generally speaking, the main research contents and achievements of this dissertation includes as bellows:(1)Discussed the mechanism of edge water and bottom water displacing oil, putted the rapid convolution integral method and water body effect function method for evaluating the energy of edge water and bottom water.(2)For flooding development reservoir, addressed the classing method for natural driving energy and the evaluating method for natural water drive development effect.(3)On the facet of formation pressure and production rate, advanced the method for how to judge whether the reservoir need to carry on a artificial water injection to supplement the formation energy or not.(4)Based on the logistic cyclothem, established the model for how to calculating and evaluating reasonable water injection rate on the different stage of reservoir development.(5)According to the analysis of flooding development situation, addressed a method for evaluating the effect of artificial water injection development, such as water displacement recovery evaluation, the analysis of deliverability variation before and after water injection, advanced the correlation method of index variation before and after water injection and the correlation method of natural indexical variation.(6)Expounded the principle of fuzzy comprehensive judgment, established the evaluating system for evaluate the development effect of flooding oil field, and put forward the evaluating method.(7)Established the optimal control numerical simulation model, advanced acorresponding solution-----the adaptive implicit method on the optimal controlcondition.(8)Using Taking the Cainan Sangonghe reservoir as an example, estimated its natural energy and evaluated the development effect of natural water driving.(9)Demonstrated the necessity of carry on artificial water injection to reinforce information energy on Sangonghe reservoir.(10)Established the mathematical model for evaluating the artificial water injection rate, assessed the water injection rate's rationality on Sangonghe reservoir's different development period, and have made a prediction.(ll)Made a reasonable evaluation for the Sangonghe reservoir's effect of artificial water injection development.(12)Fitting the Sangonghe reservoir's geologic reserve to the production history, made a further analysis of reservoir's development measures and the direction of measure adjustment.In a word, on the development process of Sangonghe reservoir, the development strategy and adjustment measure were proved be scientific and reasonable, them all make a important contribution to enhance the reservoir's recovery.