Design method of deflection azimuth for directional well in fractured formation based on geomechanics

Abstract

The invention relates to a geomechanics based design method for a deflecting azimuth of a fracture type stratal directional well. The method comprises the following steps: determining a directional well implementation purpose layer and obtaining the natural fracture occurrence, the permeability, the porosity, rock mechanics parameters and ground stress data of a reservoir through field data and an indoor experiment; drawing a hydraulic fracture and natural fracture communication capacity chart to determine a directional well deflecting azimuth range psi1 meeting the requirement of an optimal fracture communication degree; drawing a deflecting azimuth and shaft discharge capacity relationship chart to determine a directional well deflecting azimuth range psi2 meeting the requirement of the maximum discharge capacity; drawing a deflecting azimuth and shaft stability relationship chart to determine a directional well deflecting azimuth range psi3 meeting the requirement of the drilling borehole wall stability; and considering common influence of three factors of the fracture communication capacity, the shaft discharge capacity and the borehole stability to determine an optimal directional well deflecting azimuth range {psi1 n psi2 n psi3}. The design method has the comprehensive benefits of simplicity for operation, easiness for popularization, capability of ensuring the safety of a drilling shaft, high transform degree and high mining yield.

Description

technical field [0001] The invention belongs to the technical field of oil and gas drilling engineering, and in particular relates to a method for designing deflection azimuths of directional wells in fractured formations based on geomechanics. Background technique [0002] Directional wells and horizontal wells are effective ways to improve the oil and gas recovery efficiency of fractured tight sandstone, carbonate rock and shale reservoirs. The deep part of the reservoir is complex, the physical properties are poor, the porosity is low, and the permeability is low. Practice has proved that the combination of horizontal well technology and staged hydraulic fracturing technology is the most effective development method to improve and maintain single well production in tight sandstone reservoirs; The development of natural fractures in sandstone reservoirs is an inevitable geological problem. On the one hand, how hydraulic fractures communicate with natural fractures to form ...

AI Technical Summary

Problems solved by technology

This design method mainly starts from the qualitative evaluation and the indicators of deflection equipment commonly used in the field. It does not involve the mechanical model of wellbore stability, and does not consider the maximum use of hydraulic fractures to communicate with natural fractures to form a complex fracture network and stress distribution that are beneficial to oil and gas production. However, the internal relationship between anisotropic reservoir mechanical properties and wellbore stability has not been established, and the actual application effect of deflection azimuth on wellbore stability and fracturing effects cannot be reflected quantitatively. Therefore, it is urgent to develop a geomechanics-based The design method of deflection azimuth for directional wells in fractured formations to meet the requirements of wellbore stability and improvement of fracturing effects

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