Working Condition Analysis On The Oil Field Ground Water Injection System

At present, most onshore oil fields have entered the high water cut development stage. In order to maintain the stable production of the oilfields, the water injection rate increased rapidly. The electricity consumption for water injection also grown rapidly with the water cut. In the process of the water injection, how to control the ground water injection system running efficiently and stable is one of the most important tasks of the oil field. Because of the huge and complex of the oil field ground water injection system, it's very difficult to guarantee the injection allocation and energy saving in the injection system just through the experience. So we need to stimulate the working condition of the oil field ground water injection system based on the hydraulic and thermal calculate for the ground fluid network. With the calculation results, the field engineers could guarantee the oil field ground water injection system running effectively and enhance the higher level of the water injection management. In addition, some of the oil fields re-injected the produced water with hypersalinity and high temperature. Thus, it results in hardly scale building in the oil field ground water injection system. So the efficiency of the water injection system decreased greatly, in the meantime, the expenditure for the water injection is increasing. In practically, this paper has modified the existed hydraulic mathematical model for the oil field ground water injection network system which could not be solved when used in some complex ground water injection network system, made the hydraulic mathematical model adapt to more actual field conditions. Considering the influence of temperature field variation in the oil field ground injection system, this paper has established the thermal calculation model for the oil field ground injection system, and has put forward the method of coupling the ground injection network's hydraulic and thermal computational calculation. Based on the hydraulic & thermal calculation of the ground injection system and the analysis on the injection water contents, this paper has establishd the method of predicting the tendency of scale in the ground water injection pipe network. According to the above theories, the author developed the software for calculating the working conditions in the oil field ground injection system with the program language C++. With the software, we can calculate the pressure, flow rate and temperature distribute in the oil field ground injection system, attained the expected purpose of overall analysis on the working condition of the oil field ground water injection system. At the same time, it could also predict the tendency of the scale forming in the oil field ground injection network system. Depending on this, we can improve the efficiency of scale prevention in the ground injection system and gain a better benefit in economy.