In the upper formations with high angle in east Sichuan high and steep structures, some complexities, such as hole deviation, well slough, lost circulation and sticking,etc.

• 川东高陡构造上部地层倾角大 ,在钻井中极易发生井斜、井塌、井漏、卡钻等复杂情况 ,且目的层靶区要求严格。