Anti-drilling Characteristics And Bit Preference Of The Southern Margin Of The Ordos Basin

As the second largest basin in China,the Ordos Basin has the largest oil and gas fields in China and is of great strategic importance.The Ordos Basin has complex geological conditions,stratum conglomerate,soft and hard staggered,and multiple debris.The heterogeneity,compactness and low permeability of the reservoir result in low mechanical efficiency during drilling,and it is prone to stuck drilling.The complicated accidents in the underground make the exploitation of oil and gas face huge obstacles.How to achieve efficient and rapid drilling is an urgent problem we need to solve.To this end,in view of the stratigraphic characteristics of the southern margin of the Ordos Basin and the difficulties that may occur during the drilling process,this paper proposes the use of well history data to establish a drill database to analyze the applicability of drill bits in each layer,and based on the site's drilling difficulties to the existing The PDC drill bit is modified to make the improved drill bit cooperate with the safe drilling under the conditions of impact vibration drilling and drilling,reduce the wear of the drill bit and improve the service life of the drill bit,thereby improving the mechanical drilling speed and working efficiency of the drill bit,and achieving high-efficiency rock breaking.The main research contents and research results of the thesis are as follows:1.According to the geological characteristics of the southern margin of the Ordos Basin,the anti-drilling characteristics experiment(measurement of rock hardness and plasticity coefficient,determination of rock drillability,determination of rock abrasiveness,determination of rock dynamic mechanical parameters)by collecting cores,Obtain geological data of the region based on experimental data.2.Through the collection and calculation of basic logging data,the calculation of shale content and the calculation of acoustic wave time difference of shear wave,the logging data is preprocessed,and the interpretation model of formation anti-drilling characteristic parameters and logging data is established;and parameters are made to Weibei.Sampling and measuring the drilling resistance parameters such as hardness,plasticity coefficient,drillability and abrasiveness along the existing drilling data(including logging data,logging data,well history data and core data)Vertical distribution law.3.For the complex geological conditions of the Ordos Basin: the distribution of conglomerate,soft and hard staggered,multi-lithic stratum in the stratum,the individual design of the PDC bit is proposed.The improved PDC bit has the characteristics of impact resistance,anti-cone milling and high efficiency cleaning.It realizes the safe drilling in the conglomerate,soft-hard staggered and multi-chip formation with impact vibration drilling tools,which reduces the wear of the drill bit and improves the service life of the drill bit.4.Through the analysis and sorting of well history data,a database of drill bits is established,which can clearly and accurately describe the lithology of different horizons,and analyze and evaluate the drill bit data used in the area where the design well is located.The comparison criteria of the type and the important basis for the reasonable selection and use of the drill bit.