水平井在凝析气田开发中的应用及效果评价

塔里木盆地牙哈凝析气田是目前我国已投入开发的最大的整装凝析气田。凝析气藏是一种特殊和复杂的气藏,在开采过程中凝析油气体系在地层中的渗流伴随着复杂的相变,当地层流压低于露点压力时,凝析气藏会发生反凝析现象,凝析油在地层中析出,这既污染了产层,又降低了凝析油最终采收率,因此凝析气藏开发难度大、技术含量高。根据牙哈凝析气藏地质特征,在应用现代油藏工程和数值模拟技术分析论证基础上,采用水平井开发高温高压的凝析气藏。开发动态跟踪研究表明,水平井对深层和块状底水、凝析油含量高、地露压差小以及采用循环注气开发的凝析气藏具有很好的适应性,开发效果较好,经济效益明显。

THE APPLICATION AND EFFECTIVENESS EVALUATION OF THE HORIZONTAL WELLS IN THE DEVELOPMENT OF GAS CONDENSATE RESERVOIR

Yaha gas condensate reservoir of the Tarim basin is the biggest gas condensate reservoir in developing in China. The gas condensate reservoir is a kind of specific and complicated gas reservoir; during the period of the development, the system of the condensate gas percolates with complex phase transition; when the formation pressure is lower than its dew point pressure, retrograde condensation will occur in the formation, the retrograde gas condensation will hurt the producing pay and make a reduction in the final recovery of the retrograde gas condensation; so developing the gas condensate reservoir is more difficult and technical requirement is high. According to the geologic feature of Yaha gas condensate reservoir, on the base of analyzing and arguing the feasibility of using horizontal well exploiting the gas condensate reservoir by use of the modern petroleum reservoir engineering and numerical simulation, we firstly put the horizontal wells to use to develop the high temperature and high pressure in China. The exploitative dynamic analysis shows that the horizontal wells adapt to the development of deeper gas condensate reservoir with block bottom water, higher content of condensate oil, lower producing pressure difference and using the technique of gas cycling. The development effectiveness is better and the economic effect is obvious.