EFFECT OF DRILLING FLUID ON OIL AND GAS WORKERS

American Journal of Industrial Medicine, 2014

The oil and gas extraction industry is rapidly growing due to horizontal drilling and high volume hydraulic fracturing (HVHF). This growth has provided new jobs and economic stimulus. The industry occupational fatality rate is 2.5 times higher than the construction industry and 7 times higher than general industry; however injury rates are lower than the construction industry, suggesting injuries are not being reported. Some workers are exposed to crystalline silica at hazardous levels, above occupational health standards. Other hazards (particulate, benzene, noise, radiation) exist. In this article, we review occupational fatality and injury rate data; discuss research looking at root causes of fatal injuries and hazardous exposures; review interventions aimed at improving occupational health and safety; and discuss information gaps and areas of needed research. We also describe Wyoming efforts to improve occupational safety in this industry, as a case example. Am. J. Ind. Med. ß

Chemical engineering transactions, 2017

Drilling operation produces two major wastes which are produced water and drilling waste. The drilling waste must be properly managed to ensure no impact to the environment and human. The environmental and human effects of the exposure to drilling waste are discussed in the paper. Different type of drilling fluids has different composition, which influence the environmental impact of the drilling fluid. Due to the potential impact to environment and human, there are regulations by the host government and international conventions for drilling waste management. Generally, oil based drilling fluid is not permitted for offshore disposal and drill cuttings require treatment before disposal. However, water based drilling fluid is allowed for disposal. Synthetic based drilling fluid is preferred due to its technical performance and minimum environmental effects. Main regulations related to environmental and waste management in Malaysia is Environmental Quality Act and Exclusive Economic Z...

IOP Conference Series: Materials Science and Engineering

Operational discharges of spent drilling fluid, produced water, and accumulated drill cuttings from oil and gas industry are a continuous point source of environmental pollution. To meet the strict environmental standard for waste disposal, oil and gas industry is facing a numerous challenges in technological development to ensure a clean and safe environment. Oil and gas industry generates a large amount of spent drilling fluid, produced water, and drill cuttings, which are very different in every drilling operation in terms of composition and characterisation. This review article highlights the knowledge gap in identifying the different sources of waste streams in combined drilling waste. This paper also emphasises how different chemicals turn into environmentally significant pollutants after serving great performance in oil and gas drilling operations. For instance, oil based drilling fluid performs excellent in deeper drilling and drilling in harsh geological conditions, but ended with (produces) a significant amount of persistent toxic pollutants in the environment. This review paper provides an overview on the basic concepts of drilling fluids and their functions, sources and characterisation of drilling wastes, and highlights some environmentally significant elements including different minerals present in drilling waste stream.

1 Introduction There are essentially three main categories of drilling fluids: oil based fluids (OBF's), synthetic based fluids (SBF's) and water based fluids (WBF's). OBF's have been traditionally been used for their high performance drilling characteristics but tend to have a poor environmental performance in terms of their ecotoxicity and their tendency to persist in cuttings piles on the seafloor. More recently, SBF's have been developed to provide similar drilling performance as OBF's but with improved ecotoxicity and biodegradation characteristics. Synthetic based fluids include internal olefins (IO's), poly-alpha-olefins (PAO's), linear-alpha-olefins (LAO's), acetals and ester based fluids (EBF's). WBF's, whilst generally not delivering optimal performance in more challenging drilling conditions, provide the best environmental performance in terms of their non-toxic nature and enhanced ability to biodegrade rapidly on the seafloor. 2 Regulating the use of drilling fluids The Department of Minerals and Energy (DME) assesses the use of drilling fluids in perspective with environmental risks associated with the whole operation. This holistic assessment approach takes into account the technical justification for the proposed use of the drilling fluid, environmental sensitivities of the proposed drilling location, the method of cuttings disposal and the drilling fluid environmental performance under standard test protocols. Criteria for assessing the environmental performance of drilling fluids include the ecotoxicity, biodegradation and bioaccumulation properties of the whole and base fluid. Drilling using OBF's (aromatic hydrocarbons >1%) is not accepted because of the high potential for adverse environmental impacts. The use of OBF's in the bottom hole sections has reduced from 10% of all wells drilled in 1994 to 0% in 1998. The use of SBF has remained essentially the same over the same period with increasing use of EBFs. The use of SBF's may be accepted for a well subject to agreed environmental controls. Where the use of SBF is accepted, discharges to the seabed are limited to a maximum amount of 10% by dry weight of base fluid on drilled cuttings for a 311mm hole size. Currently, EBF's that demonstrate better biodegradation rates are more likely to be accepted by DME than other synthetic based fluids. No whole SBF may be discharged to the marine environment. Since the late 1980s there has been a trend towards the increased use of more technically advanced WBF's. Presently, over 80% of all wells are drilled in WA using WBF in all hole sections, and there are no restrictions on the amount of water based fluid on cuttings to be discharged to the sea. The remaining wells are drilled using WBF for the top hole sections and non-WBF in the 311mm or 216mm bottom hole sections. All drilling proposals in State waters require an Environmental Management Plan (EMP), and in Commonwealth waters require an Environment Plan (EP) as part of the application to carry out drilling operations. The EMP/EP should provide a description of the biophysical environment, potential environmental aspects and impacts and methodologies for avoiding or minimising those potential impacts. The EMP/EP should include information on the distribution and density of benthic flora and fauna, relevant site survey information and the distance of the proposed drill site from any potentially sensitive marine habitat, and information on the resilience and recovery of marine biota if this information is known. The information required of proponents is discussed in detail in Section 3 below. Drilling proposals likely to have a significant adverse

Int J Petrochem Res, 2017

The ever-increasing targets of drilling depth and reach, coupled with locational disadvantages have driven the oilfield drilling operations into new technology frontiers. Drilling fluids being an essential component of any successful drilling operation, adequate understanding of the impact of drilling fluid characteristics can eliminate a range of difficulties encountered during drilling operations and reduce drilling cost significantly. This article presents a comprehensive review of various types of drilling fluid systems and technology advancements and also the significant challenges faced by a drilling fluid engineer, starting with the basics and ending with extreme reservoir Conditions, with special emphasis on non-damaging drilling fluids. This paper is specially written for fresh petroleum engineering graduates and entry level drilling fluid engineers and drilling engineers as well as for drilling fluid research groups who would find many important information for a given drilling and reservoir challenge.

Modeling Earth Systems and Environment, 2017

isotherms and kinetics models when using the sorbent to remove pollutants such as heavy metals contained in the fluid and drilling mud to describe the adsorption process was very efficient and the Langmuir and Freundlich models usually have better performance for removing of pollutants into environment protection.

This report concerns the analysis of the basic techniques of formulating, testing and studying the properties of drilling fluid in contamination with different material encountered during drilling process. This report consists of six chapters with four experiments for measuring the physical properties of drilling fluid such as mud weight (density), rheology (viscosity, gel strength, yield point) sand content, wall building and filtration characteristics. The first chapter consists of introduction and theoretical principals of the experiment. The first experiment was about measurement of mud properties (viscosity density and pH). The second experiment was on mud properties test particularly control of mud weight. This is divided into two parts, Part A was about effect of adding bentonite on mud properties for fresh and salt water base mud and part B was about the effect of adding weight material (barite). It was observed that the viscosity and mud weight increases on the addition of salt to the fresh water mud. Also the addition of barite to the mud affects only mud weight but not viscosity because barite doesn’t have flocculating or deflocculating properties The third experiment was about drilling fluid contamination test. In this test we were studying the effect of contamination of monovalent chemicals (NaCl and KCl) and divalent chemicals that cause contamination are calcium sulfate (CaSO4), cement (Ca(OH)2, and Gypsum (CaSO4-2H2O). It was observed that Sodium chloride increases density of the drilling mud as well as the viscosity of mud since it is flocculant. Cement has a tendency of absorbing water from the mud and increase viscosity, but cement seems to have no any impact on mud weight. Experiment 4 was on determination of sand content of the drilling mud. This is a simple test designed to measure the level of particles in the mud of greater that 200 mesh or 75 microns. From the results obtained in this test and the general field experience shows that the sand content must not be permitted to rise above 2%, otherwise wear on pumps and tubulars will be the result. Any increase in sand content must be investigated since it is often an indication of poor solids removal efficiency.

The Annals of occupational hygiene, 2014

Dermal exposure to drilling fluids and crude oil is an exposure route of concern. However, there have been no published studies describing sampling methods or reporting dermal exposure measurements. We describe a study that aimed to evaluate a wipe sampling method to assess dermal exposure to an oil-based drilling fluid and crude oil, as well as to investigate the feasibility of using an interception cotton glove sampler for exposure on the hands/wrists. A direct comparison of the wipe and interception methods was also completed using pigs' trotters as a surrogate for human skin and a direct surface contact exposure scenario. Overall, acceptable recovery and sampling efficiencies were reported for both methods, and both methods had satisfactory storage stability at 1 and 7 days, although there appeared to be some loss over 14 days. The methods' comparison study revealed significantly higher removal of both fluids from the metal surface with the glove samples compared with th...

AGH Drilling, Oil, Gas

Purpose of the paper is to review environmental aspects of Oil & Gas drilling in view of economics of the projects benefiting industry professionals. Oil & Gas exploration, including offshore & directional drilling pose long and short-term environmental risks. These risks are primarily associated with (a) contamination due to drilling wastes (muds, produced waters, byproducts, etc.); emissions from drilling sites and potential runoffs, (b) natural gas/oil leaks and spills, and (c) direct effects on human health. The drilling fluids circulated through the well hole contain toxic materials (including oil/grease, arsenic, chromium, cadmium, lead, mercury, & naturally occurring radioactive materials). The composition of drilling muds and produced waters varies widely depending on location & depth of well; and type of drilling fluid. Produced waters potentially impacting the surface or groundwater are typically disposed of in a deep aquifer, but there is still the threat of accidental release from temporary storage. Contributing to air pollution are also the potential emissions of hydrogen sulfide present in natural gas deposits. Its short & long-term direct effect on human health could be severe, from unconsciousness to death within a few breaths. Statistically, 0.5-1% of exploratory wells result in blowout, causing harmful emissions. Additionally, pressurized contents of a geologic formation literally explode out of the new well, severely impacting environment and the project economics. The paper includes summary statistics of environmental incidences, their causes & preventions based on actual projects. The accidents are related to well drilling, pipelines incidents and spills/leaks listed by cause (equipment failure, corrosion, joints, materials, etc.). Paper presents guidelines and economically feasible options to minimize risks to environment & human health. It also provides an overview of the environmental concerns, project economics and sustainability issues.