毛坝1井钻井井控实践

PRACTICE OF WELL CONTROL IN DRILLING WELL MAOBA-1

南方海相地层高压气井的井控工艺有其独有的特点和难点 ,允许开展工作的压力窗口狭窄 ,能量足 ,喷势大 ,来势猛 ,失控造成的损失会非常严重。对既漏又喷的地层可以采用堵漏和提高钻井液密度压井相结合、待压稳后才继续后续作业的方法进行钻井施工。直放喷通道是气井井控的常备通道 ,长期关井和间歇放喷不利于井控安全 ,最好的办法是尽快压井。井控设备配套应在行业标准的基础上进一步强化 ,除了高压水密封试验外还必须进行高、低压气密封试验。压井需要较多的重钻井液储备和更复杂的工序。

The well control technology of high-pressure gas wells in the marine strata in South China has its unique features and difficulties. This kind of wells has a narrow permissible working pressure range, sufficient energy and strong and vigorous gas gush; and the loss caused by out-of-control was very serious. Such a drilling operation, that on the basis of combining plugging with well-killing by raising drilling fluid density, the follow-up works will not be continued until the well-killing is successfully finished, may be adopted for the formation with both mud loss and well blowout. Straight flushing channel is a commonly-prepared equipment of controlling gas well and the best way is to make the well killing as soon as possible because long-term shut-in well and intermittent flush are unfavourable for the safety in well control. Matching well control equipment should be further strengthened on the basis of professional standard and it is also necessary to carry out the high and low pressure gas sealing tests besides the high pressure water sealing test. The well killing is in need of more heavy drilling fluid and more complicated operating sequence and some thermal insulation measures should be adopted during throttling flush.