Zhang Shishu, Li Fenglin, Chang Zuping, Du Zehua, Fang Xin, Yuan Changjin, Li Zhijun
Powerchina Chengdu Engineering Corporation Limited, Chengdu 610072, Sichuan People's Republic of China.
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu 610059, People's Republic of China.
ACS Omega. 2024 Aug 17;9(34):36509-36517. doi: 10.1021/acsomega.4c04504. eCollection 2024 Aug 27.
Microbially induced calcium carbonate precipitation (MICP) provides a novel approach for use in addressing the instabilities of borehole walls comprising broken formations, but the highly alkaline environments of drilling fluids are unfavorable for microbial growth. Therefore, this study investigated the alkali-resistant domestication of commonly used in MICP. Using gradient domestication, was domesticated under different pH conditions (pH 8.0, 9.0, 10.0, and 11.0) in sodium carboxymethyl cellulose solid-free drilling fluids. Its growth patterns and variations in urease activity were analyzed to assess the effectiveness of domestication. The Gompertz and logistic models were used to fit the growth patterns of under different pH conditions, and growth kinetic models were constructed based on the mean square error, Akaike information criterion, and coefficient of determination. The bacterial concentration and urease activity of were enhanced after alkali-resistant gradient domestication. The Gompertz model accurately described the growth patterns of after gradient domestication at pH 8.0, 10.0, and 11.0, whereas the logistic model accurately described the growth pattern after gradient domestication at pH 9.0. This study provides scientific evidence and a theoretical basis for the use of in maintaining the stabilities of borehole walls comprising broken formations.
微生物诱导碳酸钙沉淀（MICP）为解决包含破碎地层的井壁失稳问题提供了一种新方法，但钻井液的高碱性环境不利于微生物生长。因此，本研究对MICP中常用的微生物进行了耐碱驯化。采用梯度驯化法，在羧甲基纤维素钠无固相钻井液中于不同pH条件（pH 8.0、9.0、10.0和11.0）下对其进行驯化。分析其生长模式和脲酶活性变化以评估驯化效果。使用Gompertz模型和逻辑模型拟合其在不同pH条件下的生长模式，并基于均方误差、赤池信息准则和决定系数构建生长动力学模型。经过耐碱梯度驯化后，其细菌浓度和脲酶活性得到提高。Gompertz模型准确描述了在pH 8.0、10.0和11.0条件下梯度驯化后的生长模式，而逻辑模型准确描述了在pH 9.0条件下梯度驯化后的生长模式。本研究为利用该微生物维持包含破碎地层的井壁稳定性提供了科学依据和理论基础。
