PRESSURE INTERFERENCE TESTING ANALYSIS OF MULTI-FRACTURED HORIZONTAL WELL WITH ASYMMETRIC FRACTURES AND NON-UNIFORM OIL PRODUCTION PROFILE: MODEL AND APPLICATION

Well interference has become a crucial factor restricting the recovery degree of unconventional reservoirs primarily due to the development method of multi-well pads with massive hydraulic fracturing. However, current interference well-test models for a multi-fractured horizontal well (MFHW) can only be applied to the simple well system, which consists of the MFHW with ideal fractures and the adjacent wells with only one operation type (production well or injection well). The accuracy of the interpretation results for well interference and fracture properties is low because of the limitations of previous models. This work has developed a multi-well interference testing model that considers the multiple operation types of adjacent wells and the asymmetrical fractures of MFHW. The influence of well spacing, fracture properties (fracture oil production rate, fracture half-length, and fracture spacing), and the operation types of adjacent wells on pressure transient behavior of MFHWs can be analyzed by the type curves simulated by the developed model. The pressure derivative curve of MFHW moves down after the elliptic flow regime due to interference from the injectors, and the radial flow regime characteristics of the system will appear later. The pressure derivative curve finally stabilized at 0.5+0.5(∑<i>q<sub>Pk</sub></i>/<i>q<sub>obs</sub></i>-∑<i>q<sub>Ij</sub></i>/<i>q<sub>obs</sub></i>) on the semi-log curve. The interference-radial will appear repeatedly when the well spacing between adjacent wells and MFHW is significantly different in the multi-well system, which overlap with each other on the type curves with similar well spacing. The proposed model has been applied in X reservoir successfully, which indicates the evaluation accuracy of the MFHW pressure transient behavior. The type curves calculated by the developed model can provide theoretical support and technical guarantee for the development of unconventional reservoirs considering the multi-well interference.