摘要
This paper aims to solve many problems which easily occur in the drilling process in the Chepaizi-Zhongguai area of the Junggar Basin,such as wellbore collapse,a relatively high content of solid phase in the drilling fluids,bit balling,low penetration rates,etc.Thus,based on an optimized fast drilling additive,a fast drilling fluid system is developed.An evaluation and analysis shows that this fast drilling additive of KSZJ has a good compatibility with the on-site drilling fluids and can improve the lubrication and inhibition performance because it is easily adsorbed at the surface of drilling string,borehole wall,and drilling cuttings.Field application shows that this developed fast drilling fluid system has many good advantages including strong inhibition performance,steady properties with heat resistance up to 160 ℃,salt tolerance degree of 10%,and cuttings recovery rate of over 80%,as well as anti-sticking,anti-sloughing and anti-bit balling,a high drag reduction efficiency,and a high penetration rate.Compared to the neighboring wells,the average ROP of this pilot well with the developed fast drilling fluid system was enhanced by more than 60%,meanwhile the complicated downhole accidents were significantly reduced and drilling risk and comprehensive cost were decreased to a high degree.With all the above good results obtained,this newly developed fast drilling fluid system plays an important role in tapping more hydrocarbon resources timely and protecting reservoirs reasonably in this study area.