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 220
- Downloads 6
OPTIMALIZACIJA RASPOREDA I IZDAŠNOSTI BUNARA U POLUZATVORENOM VODONOSNOM SLOJU
Opisan je postupak primjene linearnog programiranja za optimalizaciju rada skupine bunara u poluzatvorenom vodonosnom sloju. Predviđena ograničenja u sustavu izražena su rasporedom potencijala (sniženja ) vode u bunarima...
NEW SOURCE OF WATER FOR SETTLEMENTS ON DUGI OTOK ISLAND (CROATIA)
The water demand in Southern Croatia, where Dugi Otok is situated, is the highest during the summer due to tourism, irrigation requirements and intensive use of water by local dwellers and those in holiday-homes. The ava...
PROBNI RAD SIROKOGCELA U TANKOM SLOJU LIGNITA
Sprovedeno je probno otkopavanje širokim čelom u tankom sloju lignita. Primijenjen je polumehanizirani rad s podsijecanjem ugljenog sloja. Probni rad trajao je 6 mjeseci. Proizvodni efekti nisu postignuti i likvidacijom...
AN INVESTIGATION OF THE EFFECT OF TOUGHNESS AND BRITTLENESS INDEXES ON AMPERE CONSUMPTION AND WEAR RATE OF A CIRCULAR DIAMOND SAW
The circular diamond saw (CDS) is one of the major sawing machines in dimension stone processing plants. Predicting the performance of a circular diamond saw is very important to estimate the cost and the planning of the...
AN GEOLOGICAL OVERVIEW OF GLACIAL ACCUMULATION AND EROSIONAL OCCURRENCES AT THE VELEBIT AND THE BIOKOVO MTS., CROATIA
Numerous accumulation and erosional forms originating from the activity of small valley glaciers or cirque glaciers occur in the highest mountains in Croatia: Velebit (1757 m) and Biokovo (1762 m). They were produced dur...