Research On Fracture Identification Technology Of Low Permeability Reservoir In Huaqing Oilfield

Huaqing Oilfield is an important oil-producing area in the Ordos Basin,of which Chang 6of the Yanchang Formation is one of its main oil-bearing intervals.Due to the widespread distribution of low-permeability fractured oil reservoirs,key oil reservoirs such as the Y284 block are affected by reservoir heterogeneity.Due to the influence of strong quality and the development of micro-fractures,there are development contradictions such as the rapid rise of water cut in oil wells and the unclear direction of inter-well communication.It is urgent to carry out the identification of fractures in the study area,and to intensify the well pattern in the fracture penetration area of the test area,so as to provide a reliable basis for the next development and production of the oil reservoir in the Y284 well area.In view of the above difficulties encountered in production,this dissertation studies and analyzes the geological characteristics and reservoir heterogeneity of the Y284 area based on the arrangement of geological data,oil testing data,core data,logging data,production data and dynamic monitoring data in the study area.On this basis,the fractures in the study area are directly identified by using the core photo data and imaging logging data,and then the dynamic parameter identification method,the dynamic permeability analysis method and the rate correlation method are used to identify the fractures,and the dynamic monitoring data(water(flooding front,tracer monitoring,water absorption profile and microseismic monitoring)are mutually verified and supplemented,that is,static identification first and then dynamic identification,and a variety of quantitative fracture identification index parameters are integrated to ensure the accuracy of fracture identification;The impact of fractures on oilfield development,and intensification and adjustment of well patterns in fractured areas.Based on the above research,the main results and understandings are as follows:comprehensive analysis shows that the reservoir in the study area is highly heterogeneous in vertical and plane;the comprehensive method of "first static and then dynamic,and multiple quantitative fracture identification index parameters complement each other" is used to identify fractures 73 fractures,including 37 fractures identified by static method,16 initial fractures identified by dynamic method,and 20 fractures in production.The east-west permeability is consistent with the law of strong connectivity;combined with the current situation of the reservoir and the distribution of fractures in the test area,the two well groups Y306-57 and Y308-57 are infill and adjusted to improve the effectiveness of the oil wells.