Logging Evaluation Of Horizontal Wells In Tight Sandy Conglomerate Reservoirs Around Mahu

The tight sandy conglomerate reservoir in the M block in the Circum-Mahu region is deeply buried,the natural fractures are not developed,the reservoir properties are poor,and the heterogeneity is strong,which brings difficulties for exploration and development.Horizontal well technology has the advantages of strong production capacity and high output,which is increasingly put into production.Because horizontal well logging is different from vertical well,it is affected by factors such as formation anisotropy and environment,which brings difficulties to logging interpretation work.In this paper,the tight sandy conglomerate reservoir of the Baikouquan Formation in the M block in the Circum-Mahu region is taken as the research object,and the correction method of the horizontal well logging curve is discussed.Combined with the vertical well logging interpretation method,the horizontal wells in the study area are qualitatively and quantitatively interpreted and evaluated.The reservoirs of the Baikouquan Formation are poor in physical properties and belong to low-porosity and low-permeability reservoirs.The reservoir lithology is dominated by medium conglomerate and the shale content is low.In order to improve the accuracy of horizontal well logging interpretation,using the collected core analysis data,geological data,well logging data and oil test data,the main factors that cause the difference between the horizontal well and the adjacent vertical well logging curve are anisotropy and surrounding rock and the target layer thickness.And then the statistical method is used to establish a horizontal well logging curve which calibrated by vertical well.In order to further study the influence of resistivity anisotropy and logging environment on the dual laterolog apparent resistivity of horizontal wells,in this paper,the finite element method is used to simulate the change of apparent resistivity with resistivity anisotropy coefficient under different dip angle conditions.The core resistivity anisotropy experiment and particle swarm optimization algorithm are used to construct the resistivity anisotropy correction method.Corrected the actual horizontal well resistivity curve of the study area and achieved good results.The corresponding three-dimensional stratum physical model was established,and the influence of logging environmental factors such as surrounding rock resistivity,target layer thickness and mud resistivity on the apparent resistivity of horizontal wells was studied by using finite element method.Environmental correction method for horizontal well logging curve is set up based on numerical simulation.Using the core physics experiment and logging data,establish a reservoir quantitative interpretation model,and determine the physical and saturation lower limit of the tight glutenite reservoir,combined with the Hingle fluid identification plate to comprehensively identify the reservoir fluid properties.Finally,the horizontal well logging curve correction method was used to correct the logging curve of five horizontal wells in the study area,and combined with the reservoir quantitative interpretation model to comprehensively explain and evaluate the horizontal wells.The processing results achieve good results,and have a good degree of compliance with adjacent vertical wells.Through the research of this horizontal well correction method,correct the horizontal well curve to a vertical well,then combine the established vertical well reservoir parameter model,and a set of logging evaluation method for the horizontal well of the tight glutenite reservoir in the M block in the Circum-Mahu region is preliminarily established,which provides a reference for the horizontal well logging interpretation in the later stage of the oilfield.