A new low-cost drilling fluid for drilling in natural gas hydrate-bearing sediments

作者：Liu, Tianle; Jiang, Guosheng; Zhang, Ping; Sun, Jiaxin; Sun, Huicui; Wang, Ren; Zheng, Mingming^*

来源：Journal of Natural Gas Science and Engineering, 2016, 33: 934-941.

DOI：10.1016/j.jngse.2016.06.017

• Gas hydrate-bearing sediments
• Drilling fluid
• Good low temperature performance
• Low cost

With increasing concerns relating to nature gas hydrate exploration and development worldwide, increasing attention has been paid to drilling technology in gas hydrate-bearing sediment (GHBS). According to the drilling characteristics of hydrate formation and the existing nanomaterials, a new low-cost drilling fluid has been established through more than 120 groups of experiments for: drilling in GHBS: seawater + 2% Nano SiO2 + 3% bentonite + 1% Na-CMC (sodium carboxymethyl cellulose) + 3% SMP-2 (sulfomethylated phenolic resin) + 1% PVP (K90) (polyvinylpyrrolidone) + 2% KCI. Additionally, the traditional low-temperature performance and inhibition of hydrate formation of this drilling fluid have been evaluated. The experimental results show that this drilling fluid has optimal density, good low-temperature rheology, and sufficient shale hydration inhibition and is able to effectively inhibit free gas from undergoing hydrate dissociation near boreholes to reform the hydrate in the drilling fluid circulation system. In addition, the cost of per cubic meter of this drilling fluid is only $400-450, which is 15%-20% less expensive than existing drilling fluids for drilling in GHBS in the South China Sea. Therefore, this drilling fluid will contribute to safe and efficient borehole drilling operation in GHBS.

• 出版日期2016-7
• 单位中南大学; 中国地质大学（北京）