Analysis And Design Of Build-up Capacity Of Compound Rotary Steerable Drilling Tools

Rotary steerable drilling technology is a high-end drilling technology integrating machine,electricity,and liquid.With the development of unconventional oil and gas fields such as shale gas,complex wells such as horizontal wells,extended reach wells,and 3D multi-objective wells have emerged one after another.Conventional rotary steerable drilling tools have not been able to meet the needs of exploration and development of unconventional oil and gas resources.In addition,foreign rotary steerable drilling technology has developed in the direction of full rotation and high build slope.Therefore,it is of great significance to research and develop rotary steerable drilling tools with independent intellectual property rights in view of the urgent demand for rotary steerable drilling technology in the oil drilling industry at home and abroad and the monopoly of rotary steerable drilling technology abroad.This article is aimed at a new type of composite rotary steerable drilling tool,and focuses on the theory of build-up rate,the analysis of the bottom drill's mechanics,the influencing factors of the skewing ability and the optimization of the influence parameters.Firstly,the build-up principle of traditional rotary steerable drilling tools was analyzed.Combined with the advantages of push-the-bit drilling and point-the-bit rotary steerable drilling tools,a composite rotary steerable drilling tool was proposed.The principle of build-up and its guiding actuators were analyzed.The structure and the plunger stroke,universal joint structure,and adjustment ring structure of the guidance execution structure are designed.Then the finite element method was used to establish the bottom-drill geometry and contact non-linear static analysis model,and the drill bit lateral force calculation program for the bottom drill was designed,and the resultant force method was used for the build-up rate of the compound rotary steerable drilling tool.The capability was calculated and the geometrical buildup rate of the drilling tool calculated by the three-point circle method was 8.9°/30 m.The influencing factors of drilling tool slash ability were analyzed and it was found that the distance from the drill to the lower stabilizer,the distance from the stabilizer to the structural angle,the size of the structural angle,the distance from the structural angle to the upper stabilizer and the drilling pressure on the drill The impact of skeletal weaving has obvious effects.Finally,an optimization model of the influence factors of the bottom hole is established to optimize the influencing factors.Through the analysis,the distance from the drill to the bottom stabilizer is 0.5m,and the distance from the bottom stabilizer to the corner is 0.6m.When the stabilizer distance is between 4~9m,and the drilling pressure is between 40~90KN,the build-up rate of the bottom hole assembly can be greater than 12°/ 30 m that of the bottom hole assembly,which can meet the requirements of high build-up rate.