油基钻井液下录井参数校正方法及在风平地区应用OA

With the advancement of oil and gas exploration into unconventional and concealed reservoirs,the widespread application of highly deviated and horizontal wells has led to the effective resolution of drilling challenges in complex formations by oil-based drilling fluids,thanks to their superior wellbore stability.However,these fluids adsorb hydrocarbon substances,causing severe distortion in logging data such as cuttings logging,gas logging,and rock pyrolysis logging.Existing single-parameter correction methods suffer from poor applicability and lack supporting fluid interpretation templates,making it impossible to rely on the traditional water-based drilling fluid evaluation system,which severely restricts the accuracy of reservoir fluid identification.To address these technical challenges,this study focuses on the Fengping region reservoir as the research area,establishing a systematic multi-parameter collaborative correction method for oil-based drilling fluid logging parameters.The three-step cleaning process optimizes cuttings treatment to eliminate oil-based contamination interference.Based on the effective carbon content model of reservoir crude oil and industry-standard fitting formulas,precise correction of the S1 parameter in rock pyrolysis is achieved without residual carbon data.Through indoor hydrocarbon component adsorption simulation experiments,the adsorption rates of hydrocarbons with different carbon numbers are quantified,leading to the development of gas logging component correction formulas.Leveraging measured data from water-based drilling fluids in the same formation,a multivariate weighted regression algorithm is employed to construct a total hydrocarbon correction model.Using stable mudstone section drilling fluid immersion data as background values,quantitative fluorescence parameters are corrected.Finally,a standardized reservoir fluid interpretation evaluation template is developed.Field applications in multiple wells of the Fengping region have confirmed that this method effectively eliminates oil-based drilling fluid interference in various logging data.The corrected logging parameter interpretation results align closely with field test results,significantly improving the accuracy of reservoir fluid identification under complex conditions.This research enhances the oil-based drilling fluid logging evaluation technical system,providing reliable technical support for precise exploration and evaluation of deep shale oil and gas and tight reservoirs.