Drilling wells through the ultra-thick, salt-gypsum beds in the preCaspian basin requires an optimized drilling fluid. The pre-Caspian basin has the most promising onshore deep oil and gas bearing zones in the former Soviet Union. The basin has widely spread, ultra-thick, salt-gypsum beds in the Sagiski, Federovskoye, Adaiski, Ural-Volga, and Kolzhan-Uyaly blocks and well developed salt dome structures. Drilling of the thick salt beds, 2,000-4,000 m can lead to plastic flow of the salt, which threatens drilling safety. Proper drilling fluid density is then determined from the on-site borehole shrinkage rate required for safe drilling. This method includes creep parameters measured in the laboratory and complicated shrinkage-rate calculations of salt rocks. Analysis of borehole well rock deformation properties in deep salt beds requires an understanding of the short-term mechanical behavior of salt rock because such behavior determines the mechanisms for long-term rock deformation.
|Original language||English (US)|
|Number of pages||8|
|Journal||Oil and Gas Journal|
|State||Published - Feb 1 2010|
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Fuel Technology