���������˵���ϵ���������������꾮����

羊塔克凝析油气田是塔里木盆地发现的第一个盐下整装凝析油气田，由于该区在第三系存在大段以盐岩、“软泥岩”、石膏及膏泥岩为主的复合盐层，埋深一般在４８０８～５３２９ｍ之间，使得第一轮探井承受了较大的风险。文中就该区复合盐层钻进中遇到的技术难题进行了分析，阐述了在盐下凝析油气藏钻探中的一些成功经验，一是钻前开展盐层分布规律及地层孔隙压力分布规律的研究，以确定合理的井身结构和必封点，实际钻进中要加强地层对比，卡好层位，防止漏封盐层；二是合适的钻井液体系及性能，盐层段宜选用高密度饱和盐水ＫＣｌ聚磺防塌钻井液体系；三是采用恰当的钻进技术措施。盐层段钻进要有钻“软泥岩”的思想和技术准备，钻进中应加强划眼和短起钻，发现任何缩径及钻穿大段盐层或“软泥岩”后都要短起钻到套管鞋内静止一段时间以检查钻井液密度是否合适等等，该套技术措施的实施，安全、快速地完成了羊塔克凝析油气田的勘探任务。

Techniques of Drilling the Condensate Reservoir under Tertiary Evaporite Strata in Yangtake Condensate Field of North Talimu

Yangtake condensate field is the first integral condensate field under evaporite strata found in Talimu Basin. A larger risk was borne for drilling the first round of exploration wells because of the existence of the thick composite evaporite strata which are composed of the salt rocks, "Soft Mudstones", gypsum rocks and gypsiferous mudstones with burial depths of 4808 5329 m in general. In the paper, some technical difficulties in drilling the composite evaporite strata in the region are analyzed and some successful experiences in drilling the condensate reservoir under evaporite strata are stated. These experiences are as follows: the first is to carry out the research on the distribution laws of the evaporite strata and formation pore pressures so as to determine a reasonable casing program and the necessarily sealed points and to strengthen stratigraphic correlation and accurately identify stratigraphic horizon in drilling; the second is to choose the drilling fluid systems with suitable properties, the KCL polysulfonate hole sloughing prevention drilling fluid system with high density saturated salt water being suitable to the interval of evaporite strata; the third is to adopt right drilling measures. It is necessary to have the mental and technical preparation when the evaporite strata are met in the hole; the reaming and short trip out should be strengthened in drilling; and when any undergauge happens or after drilling through a large section of evaporite strata or "Soft Mudstone", it is necessary to trip the drilling string up to the casing shoe to test for a while so as to check up whether the density of the drilling fluid is suitable or not, etc. Through carrying out such a set of technical measures, the task of exploring the Yangtake condensate field has been finished safely and rapidly.