CONTRIBUTION TO THE METHODOLOGY OF DETERMINING THE OPTIMUM MUD DENSITY - A CASE STUDY FROM THE OFFSHORE GAS CONDENSATE FIELD D IN THE PERSIAN GULF
Journal Title: UNKNOWN - Year 2018, Vol 33, Issue 4
Abstract
Drilling the wells using water based mud through shale formations, causes their exposure to serious time-dependent wellbore instability due to shale swelling. Operating companies, before drilling operations through demanding shale formations, usually conduct drilling fluid optimization studies in order to define the proper mud type, mud density, salt type and concentration for inhibition. Through the analysis of offset wells, they are interpreting data about mud filtrate breakouts into the rock formations and chemical potential mechanisms to understand their influence on the time-de-pendent wellbore instability. The main objective of this paper is to give an insight in time-dependent and mechanical wellbore instability problems faced while drilling the wells through different shale formations in the gas condensate field D in the Persian Gulf. The importance of drilling fluid design optimization and solutions applied to overcome hole instability problems were analysed and highlighted. Besides the development of a model for mud density calculations, a concept of effective hoop stress and its influence on time dependent failure mechanisms is discussed. As a contribution to the method improvement, mud density calculation is verified by taking into the consideration the relationship between pore pressure and effective hoop stress and it is based on measured data from Well A in gas condensate field D from the Persian Gulf.
Authors and Affiliations
Damir Zadravec, Zdenko Krištafor
Keywords
Related Articles
- EP ID EP30250
- DOI https://doi.org/10.17794/rgn.2018.4.9
- Views 203
- Downloads 6
UPOTREBA RAČUNALA U OPLEMENJIVANJU MINERALNIH SIROVINA
U oplemenjivanju mineralnih sirovina računalo najčešće koristimo za potrebe simulacije postojećih odnosno projektiranje novih uređaja i procesa. Za to je neophodno poznavanje teorije procesa i odgovarajućih modela koji o...
A COMPARISON OF ARTIFICIAL NEURAL NETWORKS AND ORDINARY KRIGING DEPTH MAPS OF THE LOWER AND UPPER PANNONIAN STAGE BORDER IN THE BJELOVAR SUBDEPRESSION, NORTHERN CROATIA
Computerised mapping of subsurface strata is possible with a wide range of methods and techniques, such as geostatistical interpolation and stochastic simulations, but also with geomathematical methods. Geomathematical m...
PRIMJENA LASERA U MJERENJU PROTJECANJA FLUIDA KROZ MLAZNICE DLIJETA ZA BUŠENJE
Prikazane su dvije optičke metode za precizno mjerenje brzine protjecanja fluida: mjerenje brzine na temelju Dopplerovog efekta upotrebom lasera (LDV) i mjerenje brzine fotogramom čestica (PIV), uz postupke za digitalnu...
NEUJEDNAČENOST PRIJENOSA GIBANJA DIJAMANTNE ŽIČNE PILE ZA EKSPLOATACIJU BLOKOVA ARHITEKTONSKOG KAMENA
U radu su provedena teorijska razmatranja prijenosa vučne sile s pogonskog kotača na dijamantnu žicu i pratećih pojava koje taj prijenos izaziva uslijed isprekidanosti promjera dijamantne žice. Matematički su obrađena ko...
IOR AND EOR – CHANCES FOR INCREASE OF OIL PRODUCTION AND RECOVERIES IN EXISTING, MATURE RESERVOIRS
After the application of conventional oil extraction techniques, about 2/3 of discovered reserves still remain to be produced. In view of high probability for oil presence and oil price increases, investments in resea...