土库曼斯坦阿姆河右岸气田复杂深井超高密度钻井液技术

The Application of Ultra High Density Drilling Fluids in Complex Deep Wells in the Amu Darya Right Bank Gas Field,Turkmenistan

土库曼斯坦阿姆河右岸气田的上侏罗系基末利阶长段膏盐层（厚度为700~1 000m）是典型的异常高压地层,钻井过程中存在高压盐水侵的风险,钻井液密度高达2.48kg/L,常规钻井液不能满足安全快速钻井需要。为此,在现有饱和盐水钻井液的基础上,优选了抗高温、抗膏盐层污染处理剂,并与其他处理剂复配,研制了超高密度饱和盐水钻井液。室内性能评价试验显示,该钻井液密度可达2.48kg/L,具有高温稳定性强、润滑性好、页岩抑制能力强和抗污染能力强等特点。30多口井的现场应用表明,该钻井液能解决长段膏盐层钻进中的地层蠕变、钻井液易污染及高压盐水侵等技术难点,并能大大提高机械钻速,缩短钻井周期。

The thick gypsum salt formation （with thickness of 700-1 000 m） in the Kimmeridgian in Upper Jurassic of the Amu Darya Right Bank Gas Field has typical abnormal high pressures, there is a risk of high pressure salt water invasion in the process of drilling. For that reason, the density of drilling fluid needs to be 2.48 kg/L, and otherwise it could not meet the needs of safe and fast drilling by conventional drilling fluids. On the basis of existing saturated brine drilling fluids, the treatment agents with excellent resistance to high temperatures and pollution of gypsum and salt have been optimized. Combined with other agents, ultra high density saturated brine drilling fluids have been developed. Indoor performance tests showed that the drilling fluids could have a density up to 2.48 kg/L, and possess excellent high-temperature stability, better lubrication, higher shale resistance and anti-poUution capacities. Field application results in more than 30 wells showed that the newly developed drilling fluids could successfully eliminate salt formation creep, and solve the problem of drilling fluid pollution and the invasion of high pressure salt water during drilling in a long gypsum salt formation interval. These drilling fluids can significantly enhance the ROP and shorten the drilling cycle.