生物酶钻井液技术在大牛地气田的研究与应用

Application of Bioenzyme Drilling Fluid to Daniudi Gasfield

大牛地气田主力储层致密低渗,在钻井过程中极易受到侵入地层和黏附在井壁上的钻井化学材料或暂堵材料的伤害,造成地下流体通道不畅,影响开发效果。由于生物酶的生物降解特性可以将天然高分子钻井化学剂及暂堵材料降解为水和二氧化碳,实现对致密地层低伤害、低污染钻进,因此,在分析大牛地气田储层伤害机理的基础上,形成了生物酶钻井液配方,并进行了实验室页岩膨胀试验、降解性能试验、岩心渗透率恢复试验以及现场应用。该技术的应用实现了生产过程中致密泥饼的有效降解清除,满足了气田环境保护和可持续发展的需要。

In Daniudi gasfield, the main reservoirs are featured by low permeability. During a drilling, there are some damages from chemical and temporary plugging materials attaching to sidewall or intruding into formation, so that underground fluid passage moves not free which is unavailable for field development. With the function of biodegradation, bioenzyme may degrade these high-polymer materials to water and carbon dioxide in order to perform tight formation drilling with low damage and pollution. After analyzing certain reservoir-damage mechanisms, a formula of bioenzyme drilling fluid was developed for Daniudi gasfield, and its property was evaluated. Its application to low-permeability sandstone reservoirs in this field shows a better result, and may offer reference for other similar ones.