Optimization Design Of Trial-produce Multi-staged Fractured Horizontal Well For Tight Oil Reservoirs

Tight oil, as an important unconventional oil and gas resource, has become one of the most important hot spots both at home and abroad because of its wide distribution and huge reserves. In recent years, with the gradual improvement and application of multiple hydraulically fractured horizontal wells, the tight oil and gas has gradually become a relay domain of oil industry, and achieved industrialized and formalized mining in the North American.The exploration and development of tight oil and gas in China is still in the initial stage. The research and understanding degree are relatively low, and the development of theory and technology is still faced with many challenges.The multiple hydraulically fractured horizontal wells has become effective means for development of tight oil by changing development ideas and developing advanced technology. How to produce after hydraulic fracturing so as to achieve the production capacity of horizontal wells and obtain stable production and its change rule under the reasonable operating practice, is one of the technical problems that needs to be solved urgently in the development of tight reservoir. This paper carries out the relevant research of optimization oesign of trial-produce multi-staged fractured horizontal well for tight oil reservoirs:First, the definition, basic characteristics and classification standard of tight oil has been introduced. The development difficulties of tight oil has been summarized. The stimulation mechanism of fractured horizontal wells. The difference between the conventional fractured and multi-staged fractured horizontal wells has been contrasted.Secondly, based on the discrete fractured model(DFM), the mathematical model of conventional fractured and multi-staged fractured horizontal wells model have been established, the SRV of multi-staged fractured horizontal wells model is described by dual medium. The mathematical model has been solved by finite element method. This work provides the theoretical basis for optimization design of trial-produce multi-staged fractured horizontal well.Thirdly, the flow stages of fractured horizontal wells in tight reservoir have been shown, and the production performance has been analyzed by using the established model. The effect of pressure field and productivity by reservoir permeability, fracture length, fracture number and fracture conductivity have been analyzed. This work provides a basis for making production plan and researching of production change.Finally, the design method of trial-produce has been provided, the test schemes have been designed and implemented on the case well combined with the actual data of fractured horizontal well and the purpose of trial-produce. The well test data has been explained and the productivity of well has been predicted by the interpretation results. The research of this paper provides theoretical guidance and basis for the efficient development of multi-staged fractured horizontal wells in tight oil reservoir.