Research On Optimal And Fast Drilling Technology For Tight Oil Complex Formation

This article takes the tight oil strata in the JM block as the research objective.Difficulties discovered during the development of this block mainly include relatively well-developed micro-fractures in the reservoir core,high brittleness,poor drill ability,long drilling and completion cycles,and easy well wall collapse.In order to solve these problems,this research has carried out research on the optimal and fast drilling technology of tight oil wells in the JM area from the two perspectives of borehole stability and bit selection.(1)Utilize the logging data and related well history data collected on site,and establish the transformation relationship between dynamic and static rock mechanics parameters through the determination of indoor rock mechanics parameters.Determine the regional rock mechanics parameter profile,analyze the physical and chemical properties of the research target layer,including the changes in the microscopic characteristics of the rock after drilling fluid soaking,determine the well bore instability mechanism of the target layer,and establish the well bore instability of tight oil formations using MC criteria Model,determine the collapse pressure and fracture pressure longitudinal profile of the tight oil formation,and recommend the safe drilling fluid density window for the target layer.(2)Use the well history data collected on site,combined with the principal component analysis method and the on-site statistical analysis method to optimize the used drill bits in the target area,determine the drill bit model with good use effect,and analyze the selected drill bit model.Through indoor micro-drill simulation and sound velocity characteristic experiment,the relationship between drill ability level value and sound velocity characteristic is established,so as to determine the drill ability level value profile of the target area,integrate the used bit models,and finally determine the applicable bit model for the target horizon.The stability of the well bore and the selection of drill bits severely restrict the mechanical drilling rate of tight oil formations,extend the drilling cycle,and increase drilling costs.The relevant research based on the complex conditions of tight oil formations in this paper can solve the problem of safe and fast drilling in tight oil formations.It is of great practical significance and immeasurable economic significance to provide theoretical guidance for accelerating the exploration and development of tight oil formations in my country.