高频压力监测在水平井压裂精细诊断中的应用OA

The precise diagnosis of the fracturing effect of shale oil horizontal wells is the key to optimizing the process and increasing production capacity.In response to the limitations of traditional microseismic monitoring,such as insufficient resolution,and the tracer method being time-consuming and unable to provide real-time feedback,this study focuses on the shale oil horizontal wells in well block M and constructs a detailed diagnostic system centered on the dynamic monitoring of high-frequency pressure fields.This method is based on the transient signals of pump-stop water hammer and pressure attenuation.It deeply analyzes the application mechanisms of cepstral analysis inversion for fracture geometry,the dual-logarithmic curve of pressure derivative for discriminating the flow stage,and the negative pressure derivative for diagnosing engineering integrity.A three-dimensional diagnostic process of"structure—capacity—integrity"is established,followed by multi-well section identification and cross-validation.The research results show that:①Based on cepstral analysis,the number of fractures and the location of liquid injection points have been accurately inverted.Among the 27 fractured sections,24 sections exhibited three or more fractures,corresponding to a compliance rate of 88.9%.②The flow capacity of fractures can be clearly characterized by classifying four flow regimes:high conductivity,finite-conductivity,infinite-conductivity,and boundary-dominated flow,using log-log plots of pressure derivative.③The negative pressure derivative has been used to diagnose the sealing performance of the bridge plug in real time.The distribution characteristics of continuous sealing failure in sections 4～6 of well X1 and discrete sealing failure in the middle part of well X101 have been identified.④The comprehensive diagnosis identifies four typical fracture network morphologies:multi-level cross-fractures,thick and long straight fractures,fine and short fractures,and small-scale fracture networks.The diagnostic results have been cross-validated with logging and tracer data,achieving a comprehensive compliance rate of 85.2%.It is concluded that the high-frequency pressure field dynamic monitoring technology can achieve high-precision and real-time diagnosis of fractures and engineering anomalies,forming a complete technical chain from data acquisition,multi-dimensional diagnosis to cross-validation.This technology provides reliable technical support for the optimization of shale oil fracturing processes and the increase of single-well production capacity.