缅甸D区块高密度防塌钻井液体系室内研究

Experimental Study of High Density Anti-Sloughing Drilling Fluid for Block D in Myanmar

缅甸D区块在钻井过程中井眼坍塌严重、井径扩大率大,其原因是:地层倾角大,裂缝、孔隙发育,地层比较破碎,泥岩具有易膨胀、强分散的特点;现场使用的KCl/聚合醇钻井液抗温、抗污染、加重性能及封堵能力差。为此,优选出了以新型聚胺为主抑制剂、以白沥青为防塌剂、以抗温能力好的聚合物为降滤失剂、以磺化聚合物为流变性调节剂的新型聚胺钻井液体系。室内性能评价试验表明,新型聚胺钻井液体系的抗温能力达到150℃,抗污染性能强,具有强抑制性、良好的加重性能和封堵能力,可较好解决缅甸D区块井眼坍塌和井径扩大率的问题。

There exist serious problem of wellbore sloughing and wellbore expansion during drilling in Block D of Myanmar.The main reasons are high inclination,fractures,porosity development,brittle formation,mudstone with characteristics of expansion and strong dispersion.The temperature resistance,anti-pollution,weighting and sealing off capacities of the used KCl/polyol drilling fluid is poor.Therefore,a new type of polyamine drilling fluid was developed with polyamine as inhibitor,white asphalt as anti-sloughing agent,polymer as filtration control agent,and polysulfonate as rheology adjustor.The laboratory test shows that the new type of polyamine drilling fluid can resist high temperature up to 150℃,with excellent anti-pollution and strong inhibition,and better weighting and sealing off capacities.It can solve the problems of sloughing and wellbore enlargement in Block D of Myanmar.