The Crack Formation Mechanism And Affecting Factors Research For Mutiple Fracturing

More in sewing fracturing theory is natural fracture development of reservoirs and developed a new fracturing theory and technology.Combining WQ reservoir and co MParison analysis of reservoir examples,respectively from the natural crack open mechanism:,natural fractures and artificial fracture conditions,and the forming condition of fracture,fracturing the construction control technology,fracture process field application evaluation aspects of the study,get the following seam fracturing techniques main achievements and cognition:(1)There are two type of mutiple fractures:one is the main fracture hydraulic fracture primarily with more opening natural cracks,the other radial meshy cracks system.(2)WQ reservoir with many natural tiny cracks,tectonic fractures is in the majority.Both tension and shear fractures are relatively are well developed.So the former type of mutiple fractutres are easy to form.FH reservoir with many larger natural fractures,vertical tension fractures are well developed,easy to form radial mesh fracture system.(3)The open pressure of tiny cracks in WQ reservoir is 26 MPa,the net pressure is 10 MPa;The open pressure of large fractures in FH reservoir is 25 MPa,the net pressure is 11 MPa.(4)Temporary plugging agent and large particle size(8/16 orders)composite slug can effectively improve the pressure inside WQ reservoir seam 6-7 MPa;FH reservoir use multiple sand-up fracturing techniques,pad fluid containing(NH4)2SO4,At the end of the main fracturing,the tip screenout fracturing improve the pressure inside,in the second stage inject frash water fractureing liquid with lager rates,finally form mutiple fracture.(5)Mutiple fracturing technology in field application of reservoir WQ,Q88-82 fracturing co MPared with neighbouring well after increasing 15.4%;FH reservoir H3 through multiple fracturing well get 22m3 average oil production,which is the highest records in nearly five years among fracturing wells.