The Study Of Inverse Ground Stress With Micro-seismic Data

With the development of the petroleum industry,high permeability oil fields are less and less.In order to exploit oil and gas resources,hydraulic fracturing is the most effective method that can increase the connectivity of formation and promote the migration of hydrocarbon,but it cannot assess the results of hydraulic fracturing.To better know the extent and scope of the renovation of reservoirs,it can inverse the ground stress with seismic data to evaluate the results of fracture and then guide field hydraulic fracturing.Firstly discuss the mechanism of rock fracturing,it is reasonable to assume that the rock still meets the elastic deformation conditions while it is rupturing;build the relationship between the amplitude of hypocenter and the stress when rocks rupture by the generalized Hooke’s law.This theory constructs quantitative relationship between amplitude information and initial stress.This paper also discusses several routinely stress inversion methods,combining conventional micro-seismic data processing methods,it sets a new method to inverse ground stress with the theory and also makes the processing more evident,accurate and standardized.A homogeneous and isotropic media model has been built to verify the rationality and feasibility of the theory.Successfully to calculate the stress and fracturing pressure at hypocenter point with micro-seismic data,its errors can be ignored when comparing to the stress calculated by Anderson model.At the same time,the stress also has been inversed nearby hypocenter point and actual results different from the results of hypocenter point.It is clear that the inversion cannot only certify the accuracy of the amplitude,but also puts forward a high demand for the subsequent practical application.Overall,the model test proves that this method can be used successfully to inverse ground stress by amplitude information.