Abstract:
The shallow gas layer features in shallow burial depth, high risk coefficients, and difficult well control. Once well blowout occurs, the formation will crack, resulting in well control loss and fire hazard, casualties, and environmental pollution. In order to do well in well control and guarantee successful drilling, the author in this paper conducts research and analyzes the cases of well blowout occurred in the past few years, illustrating the causes and harm of well control in the sallow gas layer. It is proposed that you should be clear whether there is shallow gas or not before designing. During operation, abnormality in well should be discovered rapidly according to direct or indirect indication, so as to minimize all difficulties in well control. Besides, the shallow gas treatment method and several well kissing techniques are revealed. It is considered that emphasis should be laid on primary control. During operation, urgent attention should be paid to the downhole conditions, finding out abnormality in well soon and accurately, minimizing the difficulties in overflow, surface pressure, and well control, and preventing well blowout. This is of important practical significance to improving the theoretical research on well control and its field application.