Investigating low-temperature rheology of invert emulsion drilling fluids in deepwater drilling

Date

2023-8-21

Author

Yanık, Abdüssamed

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

127
views

77
downloads

Cite This

Temperature and pressure-dependent rheology of invert emulsion drilling fluids (IEDF) are the main concerns of the drilling fluids industry for deep water and ultra-deepwater drilling operations where there is a long riser section from the sea surface to the sea floor. In deepwater drilling, the wellbore temperature profile varies in a wide range, from 40°F at the riser section to 350°F at the bottomhole. IEDFs become unnecessarily more viscous in low-temperature regions and less viscous than necessary in high-temperature regions. However, high pressure affects the rheology of IEDF inversely with respect to temperature. In deep water drilling, problems such as barite sag, excessive equivalent circulation density (ECD), loss of circulation, well control and hole cleaning are the main drilling problems adversely affected by the temperature and pressure-dependent behavior of IEDFs. This study experimentally investigated the rheological behavior of synthetic-based inverse emulsion drilling fluids (SBIEDF) at low temperatures and high pressures. SBIEDFs were formulated at 10, 12, 14, and 16 ppg densities at 70/30, 80/20, and 90/10 oil/water ratios (OWR). Rheological measurements were made using the Grace M3600 automatic viscometer and M7500 Ultra HPHT Rheometer at temperatures 40, 50, 60, and 70 °F and at a shear rate range of 5.11 to 1022 s-1 from atmospheric pressure to 12,500 psi. Bingham plastic viscosity (PV), Bingham yield point (YP), and 10-second/10-minute gels were determined as a function of temperature and pressure. As a result, the rheological properties of IEDF were highly affected by temperature and pressure. The plastic viscosity of the IEDFs decreased with increasing temperature at all pressures and it increased with increasing pressure at all temperatures. The same trend but less consistent was observed for the yield point. 10-second gel strength had a decreasing trend with increasing temperature and it had an increasing trend with increasing pressure. 10-minute gels increased with increasing pressure. However, there was no consistent trend for the effect of temperature on 10-minute gels. Three IEDF samples had an increasing trend with increasing temperature while the three samples had a decreasing trend with increasing temperature. Also, it was shown that all rheological properties were increased with increasing density for all fluid samples.

Subject Keywords

Synthetic fluid, Invert emulsion, Drilling fluid, Low temperature, High pressure, Rheology, Deepwater, Drilling

URI

https://hdl.handle.net/11511/105187

Collections

Graduate School of Natural and Applied Sciences, Thesis