莺- 琼盆地高温高压区域浅层气钻井风险评估与防治

准确评估浅层气地质风险并确定合理的防治措施是海上高温高压钻井井控安全控制技术的关键环节，依据浅层气对地震速度产生不同响应的原理，建立了基于浅部地层孔隙度和密度的双参数莺- 琼盆地浅部沉积物纵波速度数学模型，结合莺- 琼盆地部分已钻井的浅部地震数据和测井资料，形成了莺- 琼盆地浅部地层岩土纵波速度趋势线，预测了蓝、黄、橙、红4 个风险等级的浅层气纵波波速变化趋势，开发了莺- 琼盆地浅层气钻井风险评估图版，制定了对应的浅层气钻井风险防治方案。通过莺- 琼盆地现场实钻应用，评估精度达到90% 以上，证明了该图版在莺- 琼盆地具有较好的成熟度。

Shallow gas well drilling risk assessment and prevention in the Yingqiong Basin area of high temperature and high pressure

The key link of well control safety technology for offshore HTHP (high temperature and high pressure) well drilling is to evaluate the geological risks of shallow gas reservoirs accurately and prepare control measures rationally. In this paper, the mathematical model on P-wave velocity of shallow sediments in the Yingqiong Basin based on dual-parameter (i.e. porosity and density) of shallow strata was established according to the principle that shallow gas responds to the seismic velocity differently. Then, based on the shallow seismic and logging data of some existing wells in the Yingqiong Basin, the P-wave velocity tendency curve of shallow strata in this basin was plotted, and its four risk levels (blue, yellow, orange and red) were predicted. And finally, drilling risk evaluation chart of shallow gas reservoirs in the Yingqiong Basin was prepared and the corresponding risk control programs were formulated. When this chart was actually applied in the Yingqiong Basin, the evaluation accuracy was over 90%. And it is indicated that this chart is better suitable for the Yingqiong Basin.