Research On Interpretation And Evaluation Methods Of Horizontal Well Logging In Shale Oil Reservoir

The Ordos Basin is located in the central region of China,spanning the five provinces of Shaanxi,Gansu,Ning,Mongolia and Shanxi.The Chang 7 reservoir is a typical shale oil reservoir in the Ordos Basin.Horizontal wells account for an increasing proportion of oilfield development,but horizontal well logging still lacks a complete evaluation system.In order to improve the coincidence rate of horizontal well logging interpretation,this paper takes the Heshui Chang 7 reservoir in the Ordos Basin as the main research object.Research on the evaluation method of logging interpretation for horizontal wells.Firstly,according to the special geological characteristics of horizontal wells,carry out the analysis of the geological characteristics of the study area,including the physical properties of the reservoir,pore throat structure characteristics and reservoir pore types,etc.,analyze the well type and logging response curve characteristics of horizontal wells in the study area.The well type analysis of horizontal wells includes the description of the main well trajectory types in the study area and the optimal design of horizontal wells.The analysis of well logging curve response characteristics includes the response of multiple logging curves for a single well.Characteristic analysis and analysis of the response characteristics of the same logging curves of the research well and the comparison well.Secondly,based on the analysis of the geological characteristics and the response characteristics of the logging curve,the petrophysical experiments of horizontal wells were carried out in a targeted manner,and the anisotropy correction coefficient was calculated by comparing the Thomson coefficient method.Corrected and applied to examples;through the numerical simulation of horizontal well dual induction and dual lateral resistivity logging,research on vertical resistivity and horizontal resistivity calculation methods of horizontal wells and analysis of response characteristics of horizontal well electrical logging are carried out.Finally,through the modeling of reservoir parameters in horizontal wells,including the determination of the shale content of the reservoir and the establishment of the logging interpretation model of porosity,permeability and saturation,the hierarchical and segmented evaluation of the reservoir in horizontal wells is carried out;based on the high-precision three-dimensional sand control modeling,The sand body slices along the well trajectory in the three-dimensional sand body are extracted,and the optimization of the wellbore trajectory and the clearer and more intuitive description of the reservoir space relationship are realized by means of human-computer interaction.The evaluation index curve reflecting the characteristics of the reservoir realizes a relatively accurate interpretation and evaluation of horizontal wells in shale oil reservoirs.