克拉2煤成大气田开发模式与开发关键技术

克拉2气田是世界少见的大型整装超高压干气气藏,开发难度非常大,经过攻关研究初步形成了此类气藏少井高产的气藏开发理念,即主力开发井采用177.8 mm(7 in)油管生产,充分利用地层能量.研究中运用储集层横向预测技术及沉积相等资料建立了克拉2气田巨厚砂岩储集层精细三维地质模型,并利用此模型对超高压气藏的开发机理进行了研究.超高压气藏产能评价不能忽略上覆压力对岩石变形的影响,动态储量计算需采用超高压有水气藏的物质平衡方程方法,而采用常规简单压降法计算的超高压有水气藏储量是实际动态储量的1.5～2.1倍.针对超高压气藏井口压力恢复曲线后期异常下降的情况,建立了利用温度场校正井口压力的方法,经过检验结果是可信的.

Development patterns and key techniques of coal-formed Kela 2 gas field

Kela 2 gas field in Tarim Basin is a rare large-scale full-contained, super-pressured dry gas field in the world, and its development is extremely complicated. After detailed technological research breakthrough, the development concept of drilling few high-production-rate wells is formed, that is, the main producing wells use 177.8 mm (7 in) diameter tubing in order to make full use of the formation energy. The fine 3D geological model of huge thick sandstone reservoirs is built constrained by the lateral reservoir prediction data, sedimentary facies data and so on. And the development mechanism of the super-pressured gas reservoirs has been studied based on this model. The rock deformation effect must be included in the deliverability evaluation. A material balance equation for super-pressured gas reservoirs with aquifer drive is derived for the dynamic reserves calculation, and the reserves derived from the conventional pressure drawdown method is 1.5 to 2.1 times the actual dynamic reserves. A temperature correction method is formed to solve the decline of the wellhead pressure build-up curves of super-pressured gas wells at the later stage, and this method is verified to be credible.