Journal of Environmental Treatment Techniques
2020, Volume 8, Issue 3, Pages: 1029-1035
J. Environ. Treat. Tech.
ISSN: 2309-1185
Journal web link: http://www.jett.dormaj.com
Drilling Fluids: Presence of Hazardous BTEXs and
Crystalline Silica
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Lakmun Chan , Nithiya Arumugam , Sathiabama T. Thirugnana and Shreeshivadasan
Chelliapan2
1
Razak Faculty of Technology and Informatics, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
2
Department of Engineering, Razak Faculty of Technology and Informatics, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur,
Malaysia
Ocean Thermal Energy Conversion (OTEC), Razak Faculty of Technology and Informatics, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra,
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5
4100 Kuala Lumpur, Malaysia
Received: 25/03/2020
Accepted: 26/06/2020
Published: 20/09/2020
Abstract
In the oil and gas industry occupational health risks due to drilling fluids is severe. Mixing room, shale shaker room and drill floor are
sites where workers are highly exposed to air pollutants, hazardous dust and even substances generated via drilling fluids associated activities.
Barite, calcium carbonate and linear paraffin or olefin-based oil are three types of chemical that are greatly used in huge quantities to prepare
drilling fluids. These drilling fluids contain hazardous substances and pose health risks. Due to the occupational health risk, Occupational
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Safety and Health Administration OSHA Europe and USA have issued guidelines for the permissible exposure limit (PEL) to be at 5 mg/m
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for barium sulphate, 10 mg/m for calcium carbonate, 0.05 mg/m for crystalline silica and 0.05 mg/m for oil mists. Therefore, this study
identified the presence of benzene, toluene, ethylbenzene and xylene (BTEX) ionic mists and crystalline silica in the drilling fluids. The grain
size distribution of additives used in the drilling fluids was also determined. The results showed the presence of BTEX and crystalline silica
based on random sampling. Therefore, the existing control measures are necessary to reduce the occupational health risks. As a control
measure, Artificial Intelligence (AI) and Internet of Things (IoT) are necessary to be introduced for the automation of drilling fluids associated
activities.
Keywords: Drilling fluids; Occupation health risk; Hazardous; BTEX; Barium sulphate
Introduction1
the drill hole via a mud pump and a discharge line. These drilling
fluids are circulated down the drill string and then out through the
bit. The drilling fluids are moved back up to the annulus and
straight into the surface. The huge quantities of drill cuttings are
composed of rocks and particulate mixtures which are released
from geological formations generated during the drilling
operation (5). Cuttings that are suspended from the hole by
drilling fluids are unwanted and removed when they flow through
the shale shaker (4). The above-mentioned drilling fluids flow
cycle is illustrated in Figure 1.
The selection of drilling fluids solely depends on their
behaviours during the operation despite their drawbacks due to
environmental concerns. The drilling fluids cycle will happen at
elevated temperature together with agitation. This potentially
exposes chemicals as well as oil vapour/mists; subsequently,
affecting the health of workers both in short-term and long-term
Drilling fluids have a vital role in measuring the success rate
of drilling operations. These fluids are important to increase the
oil recovery and shorten recovery time (1). Commonly used
drilling fluids in the oil and gas industry are water-based, oil-
based and synthetic-based muds (2). Drilling operation has three
simultaneous systems that work in a boring hole. The first is a
rotating system while second is a lifting system. The thirdsystem
is a circulating system. The rotating system rotates the drill bit
while the lifting system is used to lift up and lift down the drill
string into the hole. The circulating system will circulate fluids
around from the drill stem, out of the drill bit and up again into
the hole at the surface.
The drilling fluids are often used to eliminate cuttings from
the drilling hole, transport them to the surface and are also used
as a stabiliser and supporter to the wellbore (3). Besides, the
drilling fluids help to cool and lubricate the drill bit (4).
Preparation of drilling fluids starts at the mud mixing hopper. The
mixing hopper performs as a chemical mixing station and then the
fluids are retained in the mud pits/tanks before being pumped into
(6). Comprehensive risk assessments of drilling fluid systems
need to be conducted by the operator well planners, taking into
consideration the aspects of health, environment and safety when
deciding on the type of drilling fluids to be used for the system.
Corresponding author: Nithiya Arumugam, Department of Engineering, Razak Faculty of Technology and Informatics, Universiti
Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia. E-mail: nithiya85.a@gmail.com.
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