Human life has transformed drastically in last few decades by the discovery and exploitation of oil energy. It is utilized in making our everyday products from makeup kits to life-saving devices such as MRI machines, pacemakers and even blood donation kits. Derivatives from oil refining industry is utilized to manufacture other important products such as polymers, lubes, waxes and even bitumen for the roads. We have also been successful in taping other forms of energy such as nuclear, hydropower, solar, wind power etc.
World Energy Consumption
As per the energy data published by Institutions such as International Energy Agency (IEA) and US Energy Information Administration (IEA), Figure 1 provides a graphical representation of the various forms of energy consumed by humans every year. It can be observed that even though humans are doing much research and development work in the field of renewable energy, oil, natural gas and coal still attribute to a large percent of the human energy consumption and is also expected to remain in near future.
- Oil remains the largest energy source, accounting to about 35% of the total energy produce followed by coal at 27%.
- From 2009, China has been the world’s largest energy consumer, consuming about 20% of the total energy produced. Likewise, Asia remains the largest consumer of energy in the world and in future is expected to grow at a faster pace.
- It can also be seen from the graphical representation that with 54.9% industrial sector remains the largest consumer of energy followed by transportation (25.5%) and residential (12.6%).
Hydrocarbon molecules consisting of 1 to 60 carbon atoms form the composition of crude oil and natural gas; which are either solid, liquid or gas as per the differentiation mentioned below. They also contain impurities based on sulphur, nitrogen and / or oxygen compounds with trace quantities of other metals.
- Solid: ≥ 20 carbon atoms
- Liquid: 5 to 19 carbon atoms
- Gas: ≤ 4 carbon atoms
These are formed over millions of years by the degeneration of flora and marine fauna, pressed under high weight of sedimentation. From Figure 2, it can be seen that:
- Oil and gas, being lighter than water, rose up to fill the voids in the overlying formations.
- The upward movement is stopped by the impervious strata or nonporous rock
- They fill the spaces in porous rock seams and saturated sands, wherein the lighter gas forms the top of the heavier oil.
OPEC, a consortium of 13 countries – Algeria, Angola, Equatorial Guinea, Gabon, Iran, Iraq, Kuwait, Libya, Nigeria, Republic of the Congo, Saudi Arabia, United Arab Emirates, Venezuela, is acronym for the Organisation of the Petroleum Exporting Countries which aims to “coordinate and unify the petroleum policies of its Member Countries” ensuring:
- Stabilization of oil markets
- Steady income to producers
- Fair return on capital invested
Oil and gas exploration involves hunt for deposits of petroleum and natural gas in the Earth using petroleum geology by petroleum geologists and geophysicists, and thus to provide information required to exploit and manage the research operations; which involves:
- Establishment of database
- Investigation of available data
- Programming of surveys (mapping, geological and photo-geological)
- Performing seismic surveys and its data interpretation
- Finalizing the location of wells and its drilling
The major steps involved in the oil and gas exploration
- Preparing the rig site: Planning and preparing the area for the drilling operation
- Drilling: Attributed to this step oil and natural gas is obtained from the well
- Cementing and Testing: Ensures impermeability of the pipe
- Well completion: A perforated gun is inserted and fired generating holes connecting the oil and natural gas reservoir to the wellhead
- Fracking: Fracking fluid, a composition prepared with 99.5% water-sand mixture and 0.5% specialty chemicals, is pumped through the perforated holes, at high pressure, creating thin fissures in the shale rocks, releasing the trapped oil and natural gas.
- Production and Fracking fluid recycling: Oil and natural gas starts flowing up the well; whereas, the fracturing fluid is reused
- Well abandonment and Land restoration: Well is closed and the land is converted as it was before the drilling process
Polymers in Oil Well Drilling Fluids
Oil and natural gas drilling operations use drilling fluids (also known as drilling muds) that serve many important functions such as:
Drilling fluid, formulation consisting of a base fluid and other constituents, can be either based on oil, water, or synthetic. Other constituents can be:
- Clay (bentonite, montmorillonite etc)
- Polymer (starch, sodium carboxymethyl cellulose, polyolefin copolymer, styrene acrylate copolymer etc)
- Thinner (alkyl polyamides, complex esters etc)
- Viscosifiers (xanthan gum, guar gum acrylamide based polymers etc)
- Temperature-stabilizing agents (acrylic polymers, sulfonated (co)polymers)
- Defoamers (silicone emulsions)
- Wetting agents (alkyl polyamide complex esters)
- Proppants (resin-coated sand particles)
Some Recent Research Works:
- Madkour et al. prepared multi-walled carbon nanotube and graphene nanoplatelet reinforced thermoplastic poly(lactic acid) biodegradable nanocomposites by solution casting techniques; which provided an environmentally friendly alternative to petroleum-based polymers exhibiting enhanced thermal stability and mechanical performance
- Liu et al. firstly synthesized a copolymer of 2-acrylamido-2-methylpropane sulfonic acid, N,N-dimethylacrylamide, and 2-Hydroxyethyl acrylate by UV polymerization, and subsequently further copolymerized with cellulose nanfibrils; which was found to have better resistance to high salinity and temperature.
- Paulo et al. evaluated polymer (mixture of polyvinylpyrrolidone and hydrolyzed polyacrylamide) with bentonite for high temperature and high pressure oil wells.
- Hamad et al. determined that 0.3% amphoteric polymer (synthesized by quaternerization of disodium ethylenediamine tetraacetate with α,α′-dichloro-p-xylene) in the drilling mud formulation to be suitable for usage at elevated temperatures.
- Zhong et al. formulated β-cyclodextrin polymer microspheres for enhanced high temperature, high pressure; which can be used in combination with bentonite / carbon spheres.
- Mao et al. synthesized anionic copolymer from acrylamide, N-vinyl-2-pyrrolidone and 2-acrylamide-2-methylpropanesulfonic acid by the free radical polymerization process, found to be suitable as an anti-high temperature and anti-calcium and magnesium contamination fluid loss control additive for water-based drilling fluid.
Dear Readers, do go through the above literature and let me know your viewpoints in the Comments section.
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- Liu, Xiongli, et al. “Cellulose nanofibril-polymer hybrids for protecting drilling fluid at high salinity and high temperature.” Carbohydrate polymers 229 (2020): 115465.
- da Câmara, Paulo CF, et al. “Evaluation of polymer/bentonite synergy on the properties of aqueous drilling fluids for high-temperature and high-pressure oil wells.” Journal of Molecular Liquids 327 (2021): 114808.
- Hamad, Bahati Adnan, et al. “A novel amphoteric polymer as a rheology enhancer and fluid-loss control agent for water-based drilling muds at elevated temperatures.” ACS omega 5.15 (2020): 8483-8495.
- Zhong, Hanyi, et al. “Formulation and evaluation of β-cyclodextrin polymer microspheres for improved HTHP filtration control in water-based drilling fluids.” Journal of Molecular Liquids 313 (2020): 113549.
- Mao, Hui, et al. “Synthesis, characterization and properties of an anionic polymer for water-based drilling fluid as an anti-high temperature and anti-salt contamination fluid loss control additive.” Polymer Bulletin (2020): 1-21.