水平井技术在塔中Ⅰ号气田的适应性分析

Adaptability analysis of horizontal well technology in the Tazhong-ⅠGas Field,Tarim Basin

塔里木盆地塔中Ⅰ号气田属于碳酸盐岩油气藏，储层孔洞极其发育，但连续性差且随机分布，以往单纯用直井进行开发效果不甚理想，拟采用水平井技术进行改进。为此，运用油藏工程和数值模拟的方法，研究了储层特征对水平井的适应性，并与直井进行了比较，证实水平井在产能、单井控制储量和最终开发效果上都具有明显的优势，最后对塔中Ⅰ号气田水平井的方位、轨迹、长度等进行了优化设计。结果表明，水平井优化设计方面应尽量保证水平段方向与裂缝发育方向垂直，并用“穿头皮”思路（是指水平段距“洞”有一段距离，垂向距离一般控制在10～20m，防止钻到洞发生井漏，同时也保证完井酸化后能沟通洞）对水平段进行垂向轨迹的优化，水平段的最佳长度在600～800m。该开采技术的应用使塔中Ⅰ号气田获得了更加经济、高效的开发。

The carbonate hydrocarbon reservoirs in the Tazhong-ⅠGas Field,Tarim Basin,are full of well-developed vugs but with poor continuity and in random distribution.The previously applied vertical-well development produced unsatisfactory results,so the horizontal well technology is planned to improve the development effect there.For this reason,methods of reservoir engineering and numerical simulation were used to study the adaptability of horizontal wells to reservoir characteristics.Compared with vertical wells,some obvious advantages of horizontal wells can be demonstrated by deliverability,per-well controlled reserves,and final development efficiency.The orientation,trajectory and length of horizontal wells in the Tazhong-ⅠGas Field were also optimally designed.In this optimal design,the direction of horizontal segments should be set orthogonal to the growing direction of fractures.The idea of drilling through the scalp is used to optimize the vertical track of horizontal segments and the optimal length of horizontal segment should be 600-800 meters;while the vertical distance between the vug and the horizontal segment should be 10-20 meters,with which the vug should not be drilled through for the prevention of lost circulation but be easily connected after well completion and acid fracturing.The horizontal well technology is proved to be helpful for the economic and high-efficiency development in the Tazhong-ⅠGas Field.