Research And Application Of Key Technologies For Wellbore Structure Optimization And Drilling Speed Improvement In Shunbei Block 3

Shunbei oil and gas field is a major breakthrough in oil and gas exploration and development in Tarim Basin in recent years,with good development prospects.However,due to the characteristics of super deep,high temperature and high pressure oil and gas reservoirs in Shunbei area,it poses a great challenge to drilling engineering.Especially in Shunbei Block3 located on the No.5 fault zone,there are still technical problems such as complex formation lost circulation,wellbore instability,and low mechanical penetration rate,which seriously restrict the process of exploration and development.Based on a thorough investigation of the geological situation,stratigraphic stratification,and drilling and completion data of Shunbei Block 3,and based on the complexity of accidents occurring during the drilling process,this paper analyzes the technical difficulties of drilling in the Permian,Silurian,and Paleozoic.Through vertical and horizontal comparisons,it is clear that the technical difficulties problem in Block 3,including serious leakage in drilling operations and low ROP of Paleozoic.Secondly,in view of the serious leakage problem in the Permian and Silurian,research has been focused on the optimization design of wellbore structures.On the basis of determining the regional four pressure profile based on logging data,combined with the experience of the adjacent Tarim oilfield and the formation characteristics of Shunbei Block 3,the necessary sealing points and risk points for wellbore structure design have been determined,and two types of wellbore structure optimization design schemes have been proposed.Thirdly,in response to the technical problem of low ROP in Paleozoic drilling,a data driven "soft" drilling speed increase study was conducted,with the focus on using machine learning algorithms to optimize drilling parameters,mining the implicit logic between drilled data,and identifying the main control factors that affect penetration rate.For characteristic parameters such as drilling fluid parameters and drilling parameters,establish a mechanical penetration rate prediction model based on random forest and a drilling multi-parameter optimization model based on PSO algorithm to optimize the combination of drilling fluid parameters and drilling parameters in different formations;At the same time,the drill bit type is optimized according to the geological characteristics of Paleozoic,and the "hard" acceleration research was carried out.Using logging data as formation similarity characteristics to classify formation types,footage,ROP,and mechanical specific energy as evaluation criteria to determine different types of bit optimization indicators.Cluster analysis was used to achieve bit optimization for different formations in the region.Through the research in this paper,the difficulties in drilling technology in Shunbei Block 3 have been clarified,and the optimization design of wellbore structure and technical ideas for drilling speed increase in Shunbei Block 3 have been proposed.This has certain reference significance for reducing the complexity of drilling accidents,improving drilling speed,reducing drilling cycle,and reducing drilling costs in Shunbei Block 3.