• P. MOHAN SATYA MURTHY
• PRAVEEN GONTENA

HPHT wells are high temperature high pressure wells which are defined as those wells with a bottom hole temperature that is greater than 1500C(3000F) and requiring pressure control equipment (BOP) with a rated working pressure of above 69Mpa (10000 psi). In advances like exploration, extraction and production, some wells are reaching higher pressures and higher temperatures are known as “ULTRA HPHT WELLS” with conditions (Temperature: 2050C (or) 4000F-5000F, Pressure: 138Mpa (or) 20000-30000 psi), some wells are known as even “EXTREME HPHT WELLS” with conditions (Temperature: 2600C (or) 5000F-6000F, Pressure: 241Mpa (or) 30000-40000 psi). The major burning issue in most of the HPHT wells is the selection of suitable drilling fluid according to its properties and characteristics. We know that they are different types of drilling fluids will be used in HPHT wells. They are categorized as:  Water base systems- “DRILPLEX”, “DRILPLEX AR PLUS”, “DURATHERM”, “ENVIRONTHERM NT”, “GLYDRIL”, “K-MAG”, “KLA-SHEILD”, “POLY-PLUS”, “ULTRA DRIL”.  Oil base system- “ ECOGREEN”, “ENVIROVERT”, “MEGA DRIL”, “ RHADIANT”, “ RLELIANT”, “ VERSACLEAN/VERSADRIL”.  Synthetic base systems- “PARALAND”, “PARATHERM”.  Non-Aqueous systems- WARP advanced fluids Technology. In this project Iam mainly focusing on some specialized HPHT drilling fluids such as “GLYDRIL DRILLING FLUID”, “MICRONIZED BARITE DRILLING FLUID (WARP) TECHNOLOGY”, “INVERT EMULSION DRILLING FLUID in extreme HPHT conditions. But Iam mainly focusing on “INVERT EMULSION DRILLING FLUID” in my project. We also have some of the drilling fluid simulation software’s such as: “OPTIBRIDGE”, “PRESS PRO RT”, and “VIRTUAL HYDRAULICS”. The main objective of my project is to overcome the challenge of barite sagging issue which was happened in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature >300°F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400°F, which indicates the prevention of barite settling at high temperature.

barite sagging; invert emulsion; high-pressure high-temperature; storage modulus; sag factor

"CHALLENGES FOR DRILLING FLUIDS IN HPHT WELLS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.172-181, June-2019, Available :http://www.jetir.org/papers/JETIR1906949.pdf

"CHALLENGES FOR DRILLING FLUIDS IN HPHT WELLS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp172-181, June-2019, Available at : http://www.jetir.org/papers/JETIR1906949.pdf