大庆葡萄花油层氮气专打技术实践

Practice of Nitrogen Drilling in Putaohua Reservoir of Daqing Oilfield

摘要:

大庆油田外围葡萄花油层作为中浅层探评井开发的主要目的层，属于“三低”油藏，常规钻井方式开发成本高，经济效益差。由于受“三低”油藏地质特点的影响，常规钻进时钻井液在压差作用下产生滤液从而对储层造成一定程度的损害，受地层本身特性以及过平衡钻井2个因素共同作用，造成单井产量低。氮气作为一种循环介质在储层进行气体钻井，在储层发现和保护上具有明显优势。2011年在外围中浅层进行了葡萄花油层氮气专打钻井技术实践，从井身结构、钻井方式和完井方式3方面进行技术创新，现场试验4口井，平均钻速达24.43 m/h，为邻井常规钻井相应井段机械钻速的2倍以上，钻进过程中排砂口处即发现油流，储层保护效果好，预计增产效果显著。

Abstract:

Putaohua reservoir is the main target layer for exploration appraisal well in middle-shallow layer of periphery of Daqing oilfield, but it is a “three low” reservoir, the conventional drilling will cause high cost and low benefit; and by the characteristics of “three low” reservoir, the filtrate under differential pressure is harmful to reservoir. The formation characteristics and overbalance drilling result in low single well production. As a circulating medium of gas drilling in the reservoir, nitrogen has obvious advantages in the reservoir discovery and protection. The nitrogen drilling practice was made in Putaohua reservoir in middle-shallow layer of periphery of Daqing oilfield in 2011, technological innovation was carried out in the well structure, drilling technology and completion methods, the average penetration rate reached 24.43m/h in the 4 test wells, which was more than 2 times of that of adjacent wells by conventional drilling technology. Oil flow was found at sand draining outlet in the drilling process with good reservoir protection effects.