Research And Application Of Underbalanced Drilling Technology Of Deep Volcanic Rock In South Songliao Basin

Gas resources are abundant in south Songliao basin,the main is fractured volcanic gas reservoir,the buried depth is more than 3500 meters,the drilling depth is 4000 meters above,the pressure coefficient is 0.98-1.07,development of low-pressure gas reservoir using underbalanced drilling and completion technology was the key to improve the efficiency of exploration and development.There were difficulties such as hard lower formation,good abrasiveness,weak drillability and high geothermal gradient in drilling,this brought difficulties to the drilling operation,and there was a serious gas reservoir pollution,high pressure gas reservoir increased the difficulty of underbalanced drillin construction,thus the results of deep gas exploration and development were affected.From 2011 to the present,based on the research on the technology of underbalanced drilling and completion for the deep gas in south Songliao basin,researchs on the key technology of underbalanced drilling;underbalanced drilling fluid technology to optimize;underbalanced completion technology,and previous studys on the gas reservoir protection technology were completed respectively,the matching technology for the underbalanced gas drilling which met the exploration and development characteristics of deep gas in south Songliao basin was perfected,thereby the needs of the exploration and development of the south Songliao basin were satisfied better,the effect of the exploration and development was improved.