Investigation of local barites in drilling mugs formulation at HTHP conditions
Date
2021-04
Authors
Journal Title
Journal ISSN
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Publisher
Federal University of Technology, Owerri
Abstract
In order to counter-balance the formation pressure, the drilling mud is weighted up using a chemical additive, usually Barite. The usability of locally sourced Nigerian Barites on the major types of drilling fluids in conventional and High-Pressure-High-Temperature conditions is presented. Water-Based mud, Oil-Based mud and Synthetic oil-Based mud formulations
with locally sourced Barite were tested according to the ‘API RP 13B’. Hole cleaning capabilities of the formulations by the use of Cutting Carrying Index and Cutting Concentration
as indicators show that Osina, Gabu and Obubra Nigerian Barites with SG’s ranging from 4.0 to 4.6 are suitable for use as drilling fluid additives; with Cutting Carrying Index in the range of 23.27 to 120.54 for Water-Based mud, 0.89 to 3.98 for Oil-Based mud and 0.45 to 1.13 for Synthetic-Based mud, and Cutting Concentration of average of 4.15 vol. % at 355gpm and 300ft/hr ROP for Water-Based mud, Oil-Based mud and Synthetic-Based mud, with MAXROP of 364ft/hr under the same conditions. Moreso, laminar flow regime in the annulus is predicted for all the mud types under the same conditions and temperatures specified. CCI for water based mud decreased from ambient, 120oF, 180oF to 240oF, compared with API mud used as control sample. Oil extracted from Irvingia Gabonensis used to formulate the Synthetic-Based mud exhibited understandable physical properties such as SG of 0.836 at 60oC and a flash point of >300oC, and could serve as replacement for diesel used as base fluid in Oil-Based muds since it is also biodegradable, though the Synthetic-Based mud exhibited unfavourable characteristics in terms of low CCI value(s) and higher filter cake thickness. All the muds displayed flat or non-progressive gel; gel strengths that break with minimal initiation pressure. Locally sourced Nigerian barites have been shown to exhibit favourable properties in the mud formulations both in conventional and High-Pressure-High-Temperature drilling conditions.
Description
The master's thesis contains tables and figures
Keywords
Cutting carrying index, cutting concentration, barite, high-pressure-high temperature, mud formulation, Department of Petroleum Engineering
Citation
Omeokwe, I. K. (2021). Investigation of local barites in drilling mugs formulation at HTHP conditions (Unpublished Masters Thesis). Federal University of Technology, Owerri, Nigeria