Study Of Sand-control Hydraulic Fracturing In Dounhole

Though there are a huge number of tight oil and gas resources in Changqing Oilfield,the complexity of the reservoir characteristics make it difficult to form complex fracture networks with conventional mixed water volume fracturing technology,resulting in a limit of the stimulation performance.The bottomhole proppant concentration control fracturing technology achieving a circulating proppant concentration and displacement at the bottomhole through adjusting the annulus displacement.Comparing with the conventional fracturing,this new fracturing technology can improve the fracture network complexity and the oil production in light of the enhancement of the fracture net pressure.However,since the seldom understand of the stimulation mechanism and the lack of parameter sensitivity analysis,it is unable to optimize the fracturing design for the new fracturing technology,which make the production increasing performances of the testing wells in Changqing oilfield not stable.In this paper,the different technologies for enhancing fracture complexity are compared firstly to illustrate the feasibility of the bottomhole proppant concentration control fracturing technology.Then the performances of testing wells in Chang 7 Heshui blocks are analyzed to locate the main controlling factors.Subsequently,CDEM fracture network propagation model is established as well as the water hammer principle are utilized to clear the the stimulation mechanism of the new fracturing technology.At last,the Meyer software is used to analyze and optimize the fracturing parameters based on the geological parameters of Chang 7 formation,which has a guiding significance for the design of the bottomhole proppant concentration control fracturing.