Diagnosis And Purification Of Downhole Pollution In XC Gas Reservoir

The Jurassic gas reservoir in the XC gas field is a multi-layer gas reservoir with dense clastic rocks,which is characterized by low porosity and permeability,and most of gas wells need fracture to obtain industrial production capacity.During the exploitation of gas reservoir,the loss of the energy and production is rapid.Gas wells have characteristics of being prone to blockage,vulnerable to contamination and common effusion at the bottom of the well.Therefore,it is necessary to conduct deep research on the type of pollution and the damage mechanism of gas wells,identify the treatment measures,eliminate the damage,and restore gas well productivity.This paper is based on literature research on the damage mechanism,evaluation methods and purification technology of tight gas reservoirs at home and abroad,combined with the characteristics of XC gas reservoirs,through theoretical analysis and data statistics,supplemented by indoor laboratory evaluation and gas well contamination.There are intensive research on injury and purification.Details are as follows:?Combining with the production history of gas wells,statistical analysis of water and solid plugging samples,and other test results to judge and evaluate pollutants in XC tight gas reservoir;?Based on the analysis of experimental and laboratory data,gas well pollution types and evaluation indicators were established,gas well pollution types of XC gas reservoirs were divided,and a systematic evaluation index system was formed to guide diagnosis and analysis of the bottom hole pollution;?With the aim of proceduralization of analysis steps,quantification of parameter analysis,flow of method application,and visualization of visualization software,a system of pollution assessment and well-selection decision methods was developed.Gas well pollution damage assessment and well-selection decision software were compiled and compacted with the XC gas field.More than 70 production wells in gas reservoirs are used as examples to demonstrate the feasibility of software operation.? Development of self-generated acid descaling and demulsifiers with the goal of purification and drainage,and conducting indoor and field effect tracking and evaluation.This paper studies the bottom-hole pollution mechanism and types of gas wells in XC tight gas reservoirs,forming a method for evaluation and progressive screening.Based on this,developing a pollution evaluation and fuzzy well-selection software which can improve work efficiency,and ensure the accuracy of the judgment of pollution type.Combined with indoor and field experiment,proving the application of self-produced acid descaling and demulsification purification agents can meet the needs of gas well bottom purification,and also provides technical ideas for the efficient development of XC tight gas reservoirs.