哈萨克斯坦北特鲁瓦油田“一体化”井钻井液技术

Drilling Fluid Technology for “Integrated” Wells in North Troyes Oilfield in Kazakhstan

哈萨克斯坦北特鲁瓦油田近年来大力推行的"一体化"钻井模式,对钻井液技术提出了挑战。针对这一情况,对北特鲁瓦油田的地质工程概况和钻井液技术难点进行了分析,室内研究形成了一套饱和盐聚磺钻井液体系,并优选出2种屏蔽暂堵材料,ZD-1是一种可酸溶刚性粒子,EP-1是一种油溶性可变形颗粒,2者粒径与油层孔喉尺寸匹配,加入2%EP-1和3%ZD-1的暂堵剂后,钻井液体系的渗透率恢复值达到89%,超过了85%的控制指标,满足现场施工要求。在哈萨克斯坦的首口"一体化"井H817进行了应用,顺利钻达目的层,平均井径扩大率控制在8%以内,机械钻速提升15.2%,屏蔽暂堵钻井液技术可满足碳酸盐岩孔隙型、微小裂缝型储层保护要求,日稳产原油110 t,较邻井产量提升26.4%。

The north Troyes oilfeld （Kazakhstan） in recent years has been carrying out the “integrated” drilling mode which imposes new challenges to drilling fuid. To deal with the challenges, a saturated polymer sulfonate drilling fuid was formulated based on the analyses of geology of the formations and technical problems associated with drilling fuid operations in the north Troyes oilfeld. The saturated drilling fuid was treated with two temporary plugging agents, ZD-1 and EP-1. ZD-1 is an acid soluble rigid particle, while EP-1 is an oil soluble deformable particle. The particle size distribution of ZD-1 and EP-1 is compatible with the sizes of pore throat in the reservoir. Test of the drilling fuid treated with 2% EP-1 and 3%ZD-1 on core samples showed that the permeability recovery of the cores was 89%, exceeding the predetermined target of 85% and satisfying the needs of drilling operations. This drilling fuid formulation was used on the frst “integrated” well H817 in Kazakhstan, and the well was drilled to the designed depth successfully. Average percent hole enlargement of the well is less than 8% and the ROP is increased by 15.2%. The temporary plugging agents used are able to protect porous carbonate reservoir and reservoirs with micro-fractures from being damaged. Daily oil production rate of the well H817 is 110 t, which is 26.4% higher than the daily production rate of adjacent wells.