基于地质力学方法的深层致密气藏高效勘探技术:以库车坳陷迪北气藏为例  

Efficient Exploration Technology of Deep Tight Gas Reservoir Based on Geomechanics Method: a Case Study of Dibei Gas Reservoir in Kuqa Depression

作　　者：徐珂 杨海军[1] 张辉[1] 赵斌[1] 尹国庆[1] 王志民[1] 王海应[1] Xu Ke;Yang Haijun;Zhang Hui;Zhao Bin;Yin Guoqing;Wang Zhimin;Wang Haiying(PetroChina Tarim Oilfield Company,Korla 841000,China)

机构地区：[1]中国石油塔里木油田公司,新疆库尔勒841000

出　　处：《地球科学》2023年第2期621-639,共19页Earth Science

基　　金：国家重大科技专项“库车坳陷深层-超深层天然气田开发示范工程”(No.2016ZX05051);中国石油天然气股份有限公司重大科技专项“库车坳陷深层-超深层天然气田开发关键技术研究与应用”(No.2018E-1803)。

摘　　要：为了明确库车坳陷迪北致密气藏有利储层分布及配套工程技术,提高勘探效率,在气藏分析基础上,基于地质力学方法,综合运用地质资料、钻井资料、测井资料,开展现今地应力场预测、裂缝有效性评价等研究,兼顾甜点钻遇和压裂改造效率,从地质工程一体化角度,量化优选定向井井眼轨迹.结果表明:(1)现今地应力和天然裂缝很大程度决定了深层致密气藏品质和压裂改造效率,影响气井产能;(2)迪北气藏非均质性强,岩石物理特征、现今地应力、裂缝有效性在井间差异明显,迪北气藏裂缝甜点分布离散,储层改造难度受地质因素的制约程度大;(3)天然裂缝是深层致密气藏优质甜点区发育的重要控制因素,并能降低压裂施工难度、提高压裂改造效率;(4)定向井应多穿低应力带、多穿天然裂缝,并充分考虑天然裂缝走向和地应力方向的匹配,以提高单井产量.直井钻探模式在迪北致密气藏的高效勘探上存在局限,定向井不但能兼顾甜点钻遇和压裂改造效率,在钻井安全稳定方面也具有优势,是深层致密气藏少井高效勘探的有效途径.To clarify the favorable reservoir distribution, determine associated engineering technology, and improve the exploration efficiency in Dibei tight gas reservoir of Kuqa Depression, the in situ stress field prediction and fracture effectiveness evaluation were analyzed based on geomechanics method in this study. In addition, the efficiency of sweet spot drilling and fracturing stimulation were considered, and the directional wellbore trajectory was quantitatively optimized based on the integration of geology and engineering. The results show that:(1) the in situ stresses and natural fractures largely determine the quality and fracturing efficiency of deep tight gas reservoirs, affecting the productivity of gas wells;(2) the Dibei gas reservoir has strong heterogeneity, resulting in significantly differences in petrophysical characteristics, in situ stress and fracture effectiveness among wells. The distribution of fracture sweet spots in Dibei gas reservoir is discrete, and the difficulty of reservoir stimulation is greatly restricted by geological factors.(3) Natural fractures greatly control high-quality sweet spots of deep tight gas reservoirs, and they can reduce the difficulty of fracturing operations and improve fracturing stimulation efficiency;(4) Directional wells should penetrate more low-stress zones and natural fractures and fully match the direction of natural fractures and in situ stress to improve singlewell production. The vertical well drilling mode has limitations in the efficient exploration of Dibei tight gas reservoirs. Directional wells can take into account the efficiency of sweet spot drilling and fracturing stimulation and have advantages in terms of drilling safety and stability.

关 键 词：深层致密气藏 油气勘探 地质力学 定向井 地质工程一体化 库车坳陷 石油地质 

分 类 号：TE319[石油与天然气工程—油气田开发工程]