Study On Production Change Rule Of Horizontal Well In Super Heavy Oil Reservoir

As the horizontal well technology is more and more widely used in super heavy oil reservoir, it is quite important for the decision maker to figure out how to predict the productivity and production changing tendency of horizontal wells more reasonably and accurately in the production process. The purpose of this study is to predict the productivity of horizontal wells in super heavy oil reservoir under different developing ways more scientifically and accurately, to summarize the production characteristics, and to study the productivity decline rule of horizontal wells in super heavy oil reservoir. Then it will guide the production, and predict the super heavy oil reservoir's productivity scale more scientifically.The main factors that influence the productivity of horizontal wells in super heavy oil reservoir are determined by gray correlation analysis method. The steam dryness, steam injection volume and the length of horizontal well are very sensitive factors. A prediction formula is set up for horizontal well's productivity in super heavy oil reservoir and its analytical solution is also obtained; the result getting from the analytical solution is fitting to the real data. The productivity of horizontal wells is predicted by using BP neural network, and under the premise of knowing the first cycle's productivity, the future productivity of horizontal wells can be predicted; The paper identified the decline type of horizontal well between the cycle and in the cycle. The decline type of horizontal well between the cycles is exponential decline type. The decline type of horizontal well in the cycle is harmonic decline type. A regional geological model and the numerical model are established to predict the productivity and to forecast the productivity decline. The steam dryness,cycle steam injection volume are sensitive factors. At the same time, considering multiple factors it establishes the horizontal well's productivity prediction and decline model using the numerical simulation methods. The paper identified the decline type of horizontal well between the cycle and in the cycle; At the same time, this paper get a set of horizontal well productivity prediction methods more conveniently, effectively. From the examples of the paper, the methods to predict horizontal well productivity's accuracy is different .And it suits different stages of field development.