Evaluation Method And Its Application Research On Reservoir Fractures

Evaluation method and its application research on reservoir fractures is one of the most important tasks in the exploration and development of oil and gas fields. It is significant to study the features of reservoir fractures for oil and gas fields to increase reserve and enhance oil recovery. To meet the demands that the fine reservoir description and feasibility research on the integrate adjustment in Qian'an old block, the paper mainly completes the evaluation research on reservoir fractures of Gaotaizi reservoir in Qian'an oilfield. Firstly, by studying the features of geology and development, the paper identifies natural fractures with the information about well deviation data, core observation and geophysical logging, and interprets all the parameters of hydraulic fractures with the monitoring materials of hydraulic fracture and waterflood front. Secondly, the paper proposes a method that studying the distribution and development of hydraulic fractures starts from an aspect of the simulation about present ground stress field. Through the whole study, the paper insists that using the finite element numerical simulation of ground stress to get features of the present ground stress field in main sand bed of I block. And based on the theories of rock mechanics and hydrafrac, the paper detailedly talks about the relevance between the present ground stress field and the type, azimuth, development of hydraulic fractures, and the relationship between hydraulic fractures and natural fractures, the paper takes the development of tension cracks as a criterion that can measure the development level of hydraulic fractures. And based on the resulting data sets of the finite element simulation of ground stress field, the paper studies the law about the distribution of hydraulic fractures in the intended intervals combining with the finite element programme. Lastly, the paper checks up the predictive effect about the development lever of hydraulic fractures, and briefly talks about the influence that the development lever of hydraulic fractures affect the development of oil fields. The result shows that there are one group of natural tension crack and two groups of shear fractures in Gaotaizi reservoir of Qian'an oilfield. The type, azimuth, development of hydraulic fractures in I block are controlled by the present ground field. Under the higher differential stress, the hydraulic fracture becomes a key factor that affects the production of oil fields. With the development of tension cracks, the development of hydraulic fractures can be effectively predicted, and it offers a scientific direction in the adjustment for Qian'an oilfield.