塔里木盆地牙哈凝析气田地质特征与开发机理研究

塔里木盆地牙哈凝析气田具有地层压力高、凝析油含量高和露点压力高等显著特点。在分析其主要地质特征的基础上建立了地质模型来准确地预测储层中影响注气效果的高渗透层的分布规律。通过对凝析气田地质特征和开发机理的深入研究,发现对于高渗、高含油的凝析气藏,由于凝析油临界流动饱和度较低,可以采用衰竭式开发方式;而对于储层物性较差的高含油凝析气藏,则适合保持压力开发。据此不仅建成了我国凝析油产能规模最大的凝析气田——牙哈凝析气田,还在多个气田开发前期评价及柯克亚凝析气田综合调整中得到广泛应用,在开发实践中形成了一套适合于塔里木盆地超深高压凝析气藏的开发技术系列。

GEOLOGICAL FEATURES AND EXPLOITATION MECHANISM OF THE YAHA CONDENSATE GAS FIELD IN THE TARIM BASIN

The Yaha condensate gas field in the Tarim Basin was featured, obviously, by higher stratigraphic pressure, higher contents of condensate oil and higher dew points pressure. Based on a study on essential geological features of the condensate gas fields, a detailed geological model was set up for correctly forecasting the distribution laws of the highly permeable beds which affected the gas-injectional results in the reservoirs. The gas-liquid-solid facies changeable characteristics of high-wax condensate gas, the features of fluid facies in a condition of continuous gas-injection and the critical flowing saturation of condensate oil were analysed and evaluated. According to a detailed study on geological features and exploitation mechanisms, it was discovered that the method of exhaustion might be suitable for condensate gas pool with high permeability and high oil content, since the critical saturation degree of condensate oil being lower; while the exploitation keeping pressure might be applicable for condensate gas pool with poor physical quality of reservoirs and high oil content. In the light of these knowledges, the Yaha condensate gas field had built the largest production of condensate oil and gas in China, in addition, the Kokeya and other condensate gas fields in Tarim had widely adopted the thoughts in exploitation and evaluation of early stages. The condensate gas fields in the Tarim Basin, not only became an important base for the engineering of "gas-transportation from the west to the east", but also put forward a new model for study and exploitation of condensate gas pools with super-depth and higher pressure.