The Study Of Horizontal Well Development Technique Demarcation For Low Permeability Reservoirs

Low permeability reserve has been the most important part of the petroleum reserves in our country, most of the newly increased reserves every year are from low permeability reservoirs. Since the low permeability reservoirs have low permeability, small and complex pore structure, it presents some unique formation flow and development characteristics. Low permeability reservoirs usually display start-up pressure gradient and pressure sensitive phenomenons, so the reservoirs usually have low yield and its development is difficult. With the rapid development of horizontal well technique, it is showing great advantages in the development of low permeability reservoirs. Especiallly combined with the massive hydraulic fracturing technique, the horizontal wells have achieved great development effects in our country such as in ChangQing oil field. However, there is no sysytematic study on the horizontal well development technique in low permeability reservoirs such as the influence features of different geology and develement parameters on the horizontal and fractured horizontal well deliverability, the development characteristics of different horizontal well patterns, the optimization of horizontal welll pattern and fracture parameters, and the related technique demarcation study in low permeability reservoirs. Based on the former study and using the reservoir numerical simulation and mathematic optimization method as tools, this paper studied the influence features of different geology and development parameters on the horizontal well deliverability and the dynamic development characteristics of different horizontal well patterns. Aslo this paper estabalished an optimization meathod for fractured horizontal well, analized the development effects of the existing fractured horizontal wells and proposed some suggestions. At last, the paper studied the development technic policies based on the real low permeability reservoirs in ChanQing oil field and established the related development parameters through optimization. The work in this paper will give a guide for the horizontal well application in low permeability reservoirs.