珠江口盆地惠州凹陷火山岩酸化可行性

Feasibility study on acidification of volcanic rocks in Huizhou Sag,Pearl River Mouth Basin

为了解决珠江口盆地惠州凹陷火山岩产能低及酸化可行性的难题,通过目标储层油藏特征分析,其岩性主要为安山岩,具有岩心致密、低孔、低渗透和高温的特点。通过耐高温强溶蚀酸液体系研究,优选岩屑溶蚀率可达40.29%~61.29%的酸液体系,其主剂由质量分数为12%盐酸和30%有机氟硅酸构成,并优选了耐温180℃的高温缓蚀剂,由质量分数为4%的HZ-1和0.7%的HZ-2构成的缓蚀剂的腐蚀速率为59.33~63.86 g/(m^(2)·h),可满足行业标准;采用爆燃压裂与酸化联作的工艺可增强酸化改造能力,当表皮系数为0~3时,增产倍比为1.4~4.3,远高于基质酸化的预测数据。中国海上油田低渗透储层典型井况应用结果表明,爆燃压裂与酸化联作优势明显,该地区火山岩酸化可作为储备技术进一步提高油井产能。

To improve the low productivity and acidification feasibility of volcanic rock reservoirs in Huizhou Sag,Pearl River Mouth Basin,we analyze the characteristics of the target reservoir.The lithology is mainly andesite with a tight core,low porosity,low permeability,and high temperature.Through the research on the high-temperature-resistant and strongly corrosive acid solution systems,we select an acid solution system with a 40.29%-61.29%corrosion rate of rock debris,and the main agent is composed of 12%hydrochloric acid and 30%organic fluorosilicic acid.A corrosion inhibitor that is resistant to as high as 180℃and consists of 4%HZ-1 and 0.7%HZ-2 is selected.Its corrosion rate is 59.33-63.86 g/(m^(2)·h),which can satisfy the industrial standard.The combined process of deflagration fracturing and acidification can enhance the ability of acidification stimulation.When the skin factor is 0-3,the stimulation ratio is 1.4-4.3,much higher than the prediction data of matrix acidification.The obvious advantages of the combined process of deflagration fracturing and acidification are confirmed by the application of typical well conditions in low permeability reservoirs in China’s offshore oilfields.The acidification of volcanic rocks in this area can be used as a reserve technology to further increase the productivity of oil wells.