Study On Low-temperature Fluid Used In Tundra

With the rapid development of the western part of China, the mineral resourcesexploration and survey had further progress. In the process of exploration, thepermafrost of drilling and coring problems restrict the progress. In order to solve theproblems in drilling construction, low temperature drilling fluid on permafrost is usedfor experimental research.Through analysis of permafrost and the research status of low temperaturedrilling fluid, the characteristics of permafrost drilling is analyzed. Particularity ofeach index in the permafrost drilling is discussed. Drilling fluid of several commonlyused experimental method is compared. orthogonal experiment method is used.On the basis of laboratory experiments, NaCl is chosen as antifreeze. Throughevaluating several mud, the shandong sodium soil is chosen, Then the flocculant ofthe drilling fluid system and the fluid loss agent is selected. According to theexperimental results, low temperature and low solid drilling fluid system with saltGTQ copolymer and multifunctional agent of MBM is selected as the main agent.Through the orthogonal experiment, the condition of normal temperature and lowtemperature of formula are evaluated. And on this basis, the experimental study onthe low temperature solid frees drilling fluid system. Based on the formula thefiltration performance of adjustment, the drilling fluid formula are obtained，meetingall requirements.6groups of formula can meet-15℃and10℃, The compositionand content of the formula.Meet at15℃is used when drilling fluid formula:No.2:20%NaCl+3%+0.5%GTQ+0.5%Na bentonite-HPANNo.4:20%NaCl+3%+4.0%+0.3%Na bentonite-HPAN MBMNo.6:20%NaCl0.1%+PHP+0.1%GTQ+1.0%Na-KHM HPAN+1.0%Meet at-10℃is used when drilling fluid formula:No.1:15%NaCl+4%+0.75%GTQ+0.75%Na bentonite-HPANNo.3:15%NaCl+4%+3.0%+0.6%Na bentonite-HPAN MBMNo.5:15%NaCl0.12%+PHP+0.12%GTQ+0.5%Na-KHM HPAN+2.0%Finally, the drilling fluid formula on the solidification characteristics is obtained,Rheological properties, filtration performance, collapse prevention performance andeconomic performance are evaluated in detail. The performance of several groups offormula can met the requirements of drilling construction of permafrost region.