Study on the Low-Temperature Rheology of Polar Drilling Fluid and Its Regulation Method

Abstract

Drilling fluid is the blood of drilling engineering. In the polar drilling process, the ultra-low temperature environment puts high demands on the rheological performance of drilling fluids. In this paper, the effects of temperature, ice debris concentration and weighting agent on the rheological properties of drilling fluids were studied. It was found that the lower the temperature and the higher the ice debris concentration, the higher the drilling fluid viscosity, but when the ice debris concentration was below 2%, the drilling fluid rheology hardly changed. Secondly, the low temperature rheological properties of drilling fluid were adjusted by three different methods: base fluid ratio, organoclay, and polymers (dimer acid, polymethacrylate, ethylene propylene copolymer, and vinyl resin). The results showed that the base fluid rheological performance was optimal when the base fluid ratio was 7:3. Compared with polymers, organoclay has the most significant improvement on the low temperature rheological performance of drilling fluid. The main reason is that organoclay can transform the drilling fluid from Newtonian to non-Newtonian fluid, which exhibits excellent shear dilution of drilling fluid. The organoclay is also more uniformly dispersed in the oil, forming a denser weak gel mesh structure, so it is more effective in improving the cuttings carrying and suspension properties of drilling fluids. However, the drilling fluid containing polymer additives is still a Newtonian fluid, which cannot form a strong mesh structure at ultra-low temperatures, and thus cannot effectively improve the low-temperature rheological performance of drilling fluid. In addition, when the amount of organoclay is 2%, the improvement rate of the yield point reaches 250% at −55 °C, which can effectively improve the cuttings carrying and suspension performance of drilling fluid at ultra-low temperature.

Study on the gelation and sustained release effect of the thermosensitive material TPGS1000

“…The gelation of polymer is affected by temperature. 42 In order to evaluate the feasibility of TPGS 1000 as the thermosensitive gel carrier, the effect of temperature on gelation of TPGS 1000 was studied and the results are illustrated in Table 3. The results showed that all the samples could gel within 5 min, and GT decreased from 5 min to 2 min 30 s as the temperature increased from 35 to 38 C. Meanwhile, we found that the viscosity of the sample only increased at 34 C, but it could not gel even if it was extended to 10 min.…”

Rheological Study of Formate (Nacl) and Ethylene Glycol Based Drilling Fluid Using MATLAB

“…To significantly raise drilling process efficiency, it is important to study the rheological performance of drilling fluid. It plays a key role in successful drilling operations, downhole safety, and improving drilling speed [2].Water based drilling fluid (Water bentonite suspensions) is one of two main classes of drilling fluids used in drilling. They have a variety of applications in drilling, particularly in offshore drilling sites, because of their robust colloidal characteristics and ability to raise liquid viscosity [3].…”

“…To significantly raise drilling process efficiency, it is important to study the rheological performance of drilling fluid. It plays a key role in successful drilling operations, downhole safety, and improving drilling speed [2].…”