Study Of Leakage Mechanism And Plugging Measures Of Xujiahe Formation In Yuanba Area

Yuanba Area in northeastern Sichuan is an important exploration and development of oil and gas area in the southwest of China.The Xujiahe reservoir trap resources layer,with great potential of development,at the same time,because of very complicated geological structures,strata breakage,cracks,well leakage phenomenon is widespread and serious.Complex accidents caused by well leakage seriously affected the construction safety and single well comprehensive cost,so the study area leakage mechanism and put forward the countermeasure of plugging has important significance.Therefore,this paper takes Yuanba Xujiahe group as the research object,according to drilling,well logging data leakage,calculation and experimental simulation method combined with the actual well leakage and plugging the case study area leakage mechanism,further clarify the leak protection and plugging and difficult point,put forward countermeasures of plugging the main research contents are as follows:(1)Clearing the area well leakage characteristics and distinguishing different criteria to classify the types of leakage according to drilling and well leak data,statistical area well leakage frequency,leakage rate and leakage.The leakage reason analysis from two aspects of geological factors and construction factors;combined with drilling data and logging data,the comprehensive leakage layer discriminant method to identify the leakage position,calculation of leakage channel width,direction,permeability,porosity and leakage pressure and other characteristic parameters,and the formation of procedures for fast calculation,and then definite the emphases and difficulties of plugging work,provide the basis for subsequent experimental evaluation and Research on efficient plugging material plugging and countermeasures.(2)Rock physical information by logging data response,based on static rock mechanics,dynamic parameter transformation model,the conventional calculation method to get the area safe density window of drilling fluid.On the basis of existing logging data and wellhead location spatial distribution,establish a rapid prediction method of area safe density window of drilling fluid the fast,the conventional calculation method,the prediction method and actual drilling contrast,obtains the fast forecasting results more reliable,it has certain significance in drilling construction.(3)At present,Yuanba plugging in the comprehensive use of a variety of plugging measures,but plugging the one-time success rate is low,the previous figure out the leakage mechanism and based on the characteristics of the channel,a Novel Polymer Materials Research Institute of South China provides consolidation group performance experiments and evaluation,combining the field test,the materials meet the requirements of plugging area and can be used as efficient plugging material area of the layers.(4)Based on the leakage mechanism of polymer materials and consolidation test on the combined area of well leakage and plugging the case,determine the anti leakage measures to reasonably control the density of drilling fluid and mainly to the rapid plugging polymer consolidation plugging materials mainly to leak plugging measures,mainly,supplemented by plugging,safe and efficient treatment of well leak the problem.Plugging measures proposed in this paper can solve Yuanba Xujiahe wells leakage problems provide the basis,can effectively reduce the number of well leakage,and the leakage occurred to find leakage layer,rapid rapid plugging,to reduce the influence of leakage,the drilling safety,improve the overall efficiency has important significance.