Study On Regularity Of Fractures Distribution In Chang6 Reservoir Of B Area

Fracture is the key factor of getting the high and stable yield in the tight sandstone reservoir.Based on the systematic research and the recent study result of domestic and foreign tight sandstone gas reservoir fractures,the fracture types and its formation mechanisms are comprehensively described.Through reservoir communication,interwell tracer,interference test,water flooding front test combined with dynamic accurate identification of water direction,and the crack coalescence zone infilling method is studied.The main conclusions are as follows:(1)the fractures in the study area are mainly E-W trending fractures,S-N trending fractures formed during the Yanshan period and NE trending fractures.The present tectonic stress field in the basin of the maximum horizontal principal stress direction is north to the west,therefore,in the present tectonic stress field,the direction of maximum horizontal principal stress and NW crack opening with a higher degree of parallel.(2)based on the static and dynamic fracture test technology(tracer test,interference test,water flooding front test,waterflood index curve test,water injection profile test),and combined with the production of dynamic and oil sand body connectivity,it is concluded that there are 33 high permeability zones and 28 crackes in B209 oil production zone;11 high permeability zones and 6 crackes in B216 oil production zone;19 high permeable zones and 19 crackes in B155 oil production area.(3)study of the fracture water by NE-SW stress to the modern field control effect is obvious;at the same time,cracks have phase control pattern,turbidite fan developed relatively edge fracture;with the development of stress homogenization in water flooding process,and modern stress a conjugate direction of fracture is easy to open water leads to see.(4)the current well adaptability analysis shows that each block cracks and well fit,suggestions on the flooded area,local pattern adjustment,skewed nine spot pattern by changing the row of infill adjustment from the five spotpatterns with row spacing encryption and encryption linear water injection wells the suggestions for the district.