APPLICATION OF OPTIMIZED DRILLING TECHNOLOGY TO IMPROVE DRILLING RATE OF ULTRA-DEEP WELLS IN XUJIAWEIZI REGION

In view of the character of deep formation in Xujiaweizi region of the Songliao Basin,this paper obtained a series of technical measures,based on analysis of technical difficulties in this region,i.e.,to improve and optimize bit structure,to strengthen drilling parameter,to improve and upgrade increasingly the preferred plan of bit and drilling parameter,to prevent positively tool failure in this region,to adopt measures to strengthen drilling parameters and composite drilling technique,and to introduce in a wide area new drilling fluid system and the complete under-balance drilling techniques.A set of economical and practical measures to improve the ROP in drilling deep wells have been achieved by optimizing well structure,adopting low-pressure or negative pressure technique,and introducing composite drilling technique.