提高井壁稳定性的途径及水基防塌钻井液研究与应用进展

针对泥页岩地层黏土含量高,容易水化,导致钻井过程中出现严重坍塌和膨胀缩径,以及严重造浆等问题,从4个方面(合适的钻井液密度,提高钻井液的抑制性,减少钻井液滤液进入地层,强化封堵)阐述提高井壁稳定性的途径,介绍国内在钻井用化学剂方面开展的研究工作,同时介绍近年来出现的通过添加不同新型化学抑制剂形成的强抑制水基钻井液,如聚合醇钻井液、强抑制胺基钻井液、有机硅聚合物钻井液、有机盐钻井液、甲基葡萄糖苷钻井液等.提出围绕提高井壁稳定性的研究方向:提高对钻井液中低密度固相控制的认识,重点考虑固相化学控制剂的研究,通过低密度固相的控制,提高钻井液抑制性;考虑在现场钻井液检测性能中增加抑制性检测指标和方法;以低相对分子质量聚胺为代表的钻井液抑制剂是阳离子钻井液的新发展,应加强其机理研究;重视铝基化合物或络合物的研发,强化钻井液的抑制性及封堵作用.

The Way of Improving Wellbore Stability and Progress of Research and Application of Water-based Anti-sloughing Drilling Fluid

High content of clay and easy hydration of the shale formation may result in serious sloughing and expansion shrinkage and the severe mud-making and other issues in the process of drilling.Way of improving wellbore stability is proposed from 4 aspects:suitable drilling fluid density,improving inhibition of the drilling fluid,less filtrate of the drilling fluid into formations and enhanced plugging.The research on chemicals applied in drilling in Chinese is introduced.Strong-inhibited water-based drilling fluids,formed by adding different new-type chemical inhibitors,are introduced such as polyol drilling fluid,strong-inhibited amino drilling fluid,organosilicon polymer drilling fluid,organic salt drilling fluid and methyl glucoside drilling fluid.Finally the future research direction on improving borehole stability is put forward as following.Solid phase chemical inhibitor will be researched on improving inhibition of the drilling fluid through the control of the low-density solid phase of the drilling fluid.During the field detection of features of the drilling fluid,new index and method for detecting the inhibition should be applied.Polyamine with low molecular weight and other similar inhibitors are the new progress of cationic drilling fluid,whose mechanism should be researched.Aluminium-based compound or complex compound should be developed for enhancing the inhibition and plugging of the drilling fluid.