新型PDC钻头的防斜打快效果及评价

大庆油田海拉尔地区的地层倾角大、岩屑录井荧光级别低,亟待解决满足岩屑录井要求的防斜打直问题。为了能够在获得足够大的岩屑颗粒和提高机械钻速的基础上达到防斜打直的目的,制定了采用大切削齿B425型PDC钻头配以小钟摆钻具组合的现场试验方案。试验表明:B425钻头与牙轮钻头所破碎的岩屑颗粒基本相当,能够满足地质岩屑录井的要求;与牙轮钻头相比,B425钻头显著地提高了机械钻速,降低了钻头费用,减少了起下钻次数;单只B425的进尺可达1000m以上,相当于2~3只牙轮钻头的进尺;采用PDC钻头配以小钟摆钻具组合,可以较好地解决防斜打直问题。此外,针对试验中遇到的问题,通过改进井身结构和调整钻井参数,形成了一套适合于海拉尔地区的防斜打快技术。

Effect and Evaluation of Novel PDC Bit for Deflection Control and Fast Penetration

Because of the large formation dip angle in Hailaer area of Daqing Oilfield, deflection control is very difficult; while the fluorescence grade of cuttings is low, cutting logging is also a problem. To obtain cuttings debris large enough for cutting logging, and at the same time improve ROP, so as to achieve the goal of deflection control and vertical drilling, a testing plan is made by using the Model B425 large cutter PDC bit, and combining with the use of small pendulum BHA. Tests show that the debris cut by model B425 PDC bit almost have the same size with that of by roller cone bit, and it can meet the requirements of geological cutting logging. As compared with the roller cone bit, model B425 bit effectively improves ROP and cuts down bit cost, and it minimizes the tripping times. The footage of a single B425 bit can reach to over 1000m, which is the footage about 2 to 3 roller cone bits. By applying PDC bit combining with small pendulum BHA, good effects are achieved for deflection control and vertical drilling. In addition, according to the problems in the tests, and by modifying the casing program and adjusting drilling parameters, a set of deflection control fast penetration technology is thus established.