“等电位”钻进与“零电位”钻井液初探

Primary Study on Isoelectric Drilling Method and Zero Potential Drilling Fluid

对"等电位"钻进技术概念和"零电位"钻井液技术概念做了介绍。"等电位"钻进概念认为岩石表面的zeta电位为零,即等电位(IEP)状态时,能够提高钻进速度和延长钻头寿命,从而提高钻进效率。"零电位"钻井液则是将目前使用的zeta电位(-40^-35 mv)的钠基膨润土变为"零电位"(-5^+5 mv)的膨润土,改钻井液的"阴离子悬浮体系(ζ电位>-45 mv)"为"阳离子悬浮体系(zeta电位接近零电位)",再将其它阴离子型的处理剂如降滤失剂、提粘剂等改变为阳离子型或非离子型,配成具有相应性能的钻井液。钻进试验表明,"等电位"钻进和"零电位"钻井液可有效提高钻进效率。提出了几点开展相关研究的认识。

The concepts of isoelectric drilling method and zero potential drilling fluid are presented.By the concept of isoe-lectric drilling method, zeat potential on rock surface is zero, that is, in IEP state, both penetration rate and bit service life can be improved with consequent higher drilling efficiency.As for zero potential drilling fluid, that is changing currently used Na-bentonite with zeta（-40^-35 mv） potential into bentonite with zero potential（-5~＋5 mv）;changing“anion suspension system（ζpotentia〉-45 mv）”of the drilling fluid into“cationsuspension system（ zeta potential close to zero potential）”and changing anionic treating agents, such as filtrate reducer and viscosifier, into cationic or nonionic ones to form the drilling fluid with the corresponding performance.Drilling experiment shows that drilling efficiency can be effectively improved by isoelectric drilling method and zero potential drilling fluid.Some understandings of the relevant research are put forward.