Technology for Precise Positioning of Ultra-deep Fracture-porous Carbonate Reservoirs
The fracture-porous carbonate reservoirs in the Tarim Basin is deeply buried,and have small storage spaces and strong heterogeneity,bringing difficulties to accurate location of reservoirs and precise positioning of reservoir spaces.This poses great challenges for well-targeting and optimizing drilling trajectories,and limits well deployment and rapid production.To address these challenges,a study on precise reservoir positioning driven by VSP(Vertical Seismic Profile)was conducted using pre-stacked seismic data such as gathers and velocity fields,as well as VSP data collected during drilling operations.By optimizing the processing work-flow,the timeliness of delivering results within 72 hours was ensured,and precise positioning of the reservoir was achieved without affecting the drilling speed.This method has been successfully applied in the real-time tracking of more than 120 wells,resulting in an improvement in the direct drilling encounter rate of the reservoirs from 60%to 80%,and increasing in the success rate of drilling to over 90%.It provides valuable insights for reservoir prediction and precise positioning in similar fracture-porous reservoirs.