Simulation And Optimization Of Water Injection Pipe Network

On the basis of research on the related theories regarding geographic information techniques, optimization theory and engineering fluid mechanics, the spatial data models of geographic information system and water injection pipe network of engineering fluid mechanics are applied to simulate and optimize the oilfield water injection pipe network. Necessary measures of engineering and optimal operation must be taken to realize the oilfield energy saving.The water injection system can be simulated to some extent with the application of geographic information system and its web issuing system. In addition, the spatial inquiry and layout optimization of water injection system can be implemented with spatial analysis techniques such as analyses of buffer and stack-up. The managers handle the operation of water injection pipe network with the help of geographic information system, providing reliable data support for the operators to make the program.Building geospatial data models aims at simulating spatial information of water injection system to some extent. Moreover, the functions of data loading, inquiring, statistics, analyzing and updating can be achieved by spatial data management developed in the geographic information softwares such as Geomedia Professional and ArcGis. Furthermore, information of water injection system can be shared in the company, providing the professional diagrams in different proportions for different systems and any thematic map stack-up, analysis, display, inquiry and output can be made according to the requirements.The vector graphics of water injection system information are issued with the application of GeoMedia Web Map, including graphic information of water injection system as well as inquiry and statistic of attribute data associated with graphic information. The graphics of water injection system in static database of surface engineering is issued with the help of WebGIS,so is the production performance information associated with water injection system of surface engineering, which can be kept in accordance with the production performance. And also graphics of water injection system in surface engineering are related to production performance information. The operators inquire about the information of the water injection system on the lan visually at anytime and learn the operation of the water injection system in time and accurately.Solving unconstrained optimization problems consists of the steepest descent method, Newton method, the conjugate gradient method, DFP of the quasi-Newton method and BFGS method etc. Solving constrained optimization problems include exterior penalty function method, interior penalty function method and penalty function method of mixed type. The optimization of water injection pipe network consists of layout optimization and parameter optimization for pipeline network. The overall mathematical model for water injection pipe network is built for layout optimization, including layout optimizations of well groups, water allocating room and water injection station. Layout optimization is solved with optimum algorithm such as DFP and BFGS and the optima is obtained. The mathematical model for water injection system is built based on the main considerations such as pipeline costs as well as consumptions of motive energy and heating energy of the pipe network, and the optimal economical pipeline diameter can be determined.The calculation of the water injection pipe network is to solve flow rate of the water injection pipe network and head loss by making adjustment calculation to water injection pipe network using continuity equation, energy equation and pressure drop equation. It mainly consists of methods of solving node, section and ring etc. The method of solving node consists of simple iterative method and Newton-Raphson Method and method of solving ring consists of Hardy Cross method. There are the least equations in the method of solving ring, accordingly the calculations are the least. But continuity equation must be satisfied when initial flow rate of section is determined resulting in complicated distributing of initial flow rate. Whether the designed initial flow rate is proper or not has significant effect on convergence, moreover loop matrix information of pipe network needs to be input. The equations in the method of solving section are the most and also loop matrix information needs to be input, in addition, coefficient matrix is asymmetry. The method of solving node is listed according to the flow balance of the node, the distribution of initial flow or initial water head are easy. So no matter how the initial values of section flow is distributed, flow balance is satisfied during repeating iteration resulting in simplifying the preparation before computation. Because of its little storage and fast computation, the method of solving node is used while calculating large scale pipe network.By making adjustment calculation for oilfield water injection pipe network, operation information of pipe network is provided for the production management, and optimizing pipe network with the application of optimal techniques, more reasonable programs for water injection pipe network is made, then necessary engineering measures must be taken to achieve the optimization and the programs. The integrated reconstruction of the pipe network is implemented based on hydraulic calculation, which includes local pressure boosting of water injection wells, impeller cutting and pump stage reduction and local layout optimization of pipe network. Energy consumption of oilfield water injection pipe network is reduced by decreasing pressure drop of pipe network and differential pressures of pump tube and well pipe.