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In many operations worldwide, surface waters are injected into producing formations to enhance oil recovery. The types of surface waters used range from seawater (salt water) to lake water (brackish) to river water (fresh water). Surface water must be treated to remove undesirable components before injection. Treatment of surface water for injection requires a specially designed system made up of various components to remove or control any contaminants in the water. The system is engineered to perform the required treatment in the most cost-effective and environmentally sensitive manner. A typical system is shown in Figure 1. Commonly used methods for removal or control of these contaminants are discussed in this section. Surface waters normally contain suspended solids particles that, if injected into the producing formation, will plug the injection well. The type, concentration, and particle-size distribution of suspended solids in water will vary depending on the source of the surface water.
Documentaries are used both to educate and tell stories that their makers believe should be heard. That applies to documentaries about the inner workings of various industries such as oil and gas. To many outside the petroleum industry, those inner workings are a black box: Money and engineering goes in, gasoline and petrochemical products come out. It is also full of stories, making it an industry ripe for documentarians. The following reviews consider a small handful of the documentaries covering the petroleum industry and what might be learned from them beyond their immediate message.
Recent field studies have shown that measurements taken with aerial light detection and ranging (LiDAR) are more effective in discovering various sources of methane emissions than onsite optical gas imaging (OGI) and that policy and regulations that rely on OGI surveys alone risk missing a significant portion of total emissions. While emissions reduction depends on the frequency, distribution, and magnitudes of source types, recent field studies have shown that a small proportion of sources or sites is responsible for most methane emissions and that measured emissions significantly exceed estimates, often by 50% or more. A recent paper published by Environmental Science & Technology presents how researchers are using the disparity in these estimates to sharpen inventory estimates at upstream oil and gas sites. Traditionally, the differences between estimated and actual emissions have been attributed to what are called "fugitive" emissions from leaking components detected by optical gas imaging (OGI) cameras. Some disagreement exists, however, as to what constitutes fugitive vs. vented sources and, if the source is vented, what is considered normal vs. abnormal venting.
Petroleum engineering is and will be needed for decades to come to provide the required energy for the world and help alleviate the challenges of climate change. Of course, petroleum engineering will evolve into energy transition as it has been changing since its inception in modern history with the Drake well in 1895, located in Pennsylvania. At the same time, we will continue to use the current practices in our daily operations. Petroleum engineering practices can and will also be used in solving some of the climate change issues. This information is described in detail in SPE 200771 (Kamal 2020).
Two of the biggest oilfield service companies in the world reported earnings this week and reiterated that while things are getting better, a total recovery from the pandemic-driven downturn is not on the agenda in the short term. Halliburton is coming off a relatively hot quarter and reported $227 million in profits, a 33% increase over the previous period. After reporting a total revenue of more than $3.71 billion, the company's earnings amounted to 26 cents per share which beat most analysts' expectations of 22 cents. The needle moved the opposite direction for Baker Hughes which reported an adjusted quarterly net income of $83 million, a 9% drop from the first 3 months of the year. Baker Hughes finished the quarter with earnings per share of 10 cents which missed the market estimate of 16 cents.
BP has entered a contract with Sempra Energy and Mexico's Infraestructura Energetica Nova for delivery of the company's first carbon-offset liquefied natural gas cargo. The cargo was delivered on 16 July to the Energia Costa Azul terminal, a joint venture between Sempra and IEnova, in Mexico's Baja California. The cargo will be sourced from BP's global LNG portfolio, and its estimated emissions will be offset using carbon credits sourced from a BP forest creation project in Mexico. "We are excited to advance our goal to lower GHG [greenhouse-gas] emission intensity at our LNG facilities," said Justin Bird, chief executive of Sempra LNG. "Sempra LNG continues to build a strong business portfolio focused on sustainability and the global energy transition."
Water is the most commonly used fluid in hydraulic fracturing, and it is used in large quantities. Chemicals are added to the water to aid in fracturing and prevent damage to the reservoir, and normally less than 1 percent of the fluid contents are chemical compounds. Because fracturing involves a large amount of water, innovations to reuse/recycle and safely dispose of the water are an important part of environmental stewardship. Hydraulic fracturing is the process of pumping fluid into a wellbore at an injection rate too high for the formation to accept without breaking. During injection, the formation's resistance to flow increases, and the pressure in the wellbore increases to a value called the break-down pressure, which is the sum of the in-situ compressive stress and the strength of the formation.
Multiple types and sources of water streams are encountered in oil and gas operations; the two primary ones are produced and surface water. Produced water is the brine that comes from the oil reservoir with the produced fluids; surface water encompasses fresh (river or lake) and saline (seawater) sources. Water sources are treated for disposal, injection as a liquid, or injection as steam with three types of facilities. Produced water is treated in offshore operations for overboard disposal or injection into a disposal well, but when onshore, it is treated for surface disposal, liquid injection, or steam injection. In all instances, the produced water must be cleaned of dispersed and dissolved oil and solids to a level suitable for environmental, reservoir, or steam-generation purposes. Surface water is treated offshore for liquid injection and onshore for liquid- or steam-injection purposes. In all instances, the surface water must be cleaned of dispersed and dissolved solids to a level suitable for reservoir or steam-generation purposes. In oil-producing operations, it is often desirable to inject water or steam into the formation to improve oil recovery. Water injection for this purpose is called a waterflood; when properly implemented, it will maintain reservoir pressure and significantly improve the oil recovery vs. primary production. Steam injection, known as a steamflood, will reduce the viscosity of oil and further enhance the oil recovery. See the chapter on Steam Injection in the Reservoir Engineering and Petrophysics volume of this Handbook. In offshore areas, governing regulations specify the maximum hydrocarbon and solids content in the water allowed in overboard discharges. Some studies have estimated that during the life of a well, 4 to 5 bbl of water are produced for every barrel of oil, making this fluid the largest volume of produced product in the oil and gas industry. This chapter discusses the equipment and design criteria used in common water-treatment systems for disposal or injection. In addition to the removal of dispersed or dissolved hydrocarbons and solids, the water-treatment engineer may be concerned with chemical treatment, material selection, and solids disposal, which are also covered. Produced water typically enters the water-treatment system from a two- or three-phase separator, free-water knockout, gun barrel, heater treater, or other primary-separation-unit process. This water contains small concentrations (100 to 2000 mg/L) of dispersed hydrocarbons in the form of oil droplets. Because the water flows from this equipment through dump valves, control valves, chokes, or pumps, the oil-particle diameters will be very small ( 100 μm). Treatment equipment to remove dispersed oil from water relies on one or more of the following principles: gravity separation (often with the addition of coalescing devices), gas flotation, cyclonic separation, filtration, and centrifuge separation.
Water sources are treated for disposal, injection as a liquid, or injection as steam with three types of facilities. Produced water is treated in offshore operations for overboard disposal or injection into a disposal well. Water sources are treated for disposal, injection as a liquid, or injection as steam with three types of facilities. Surface water is treated offshore for liquid injection and onshore for liquid- or steam-injection purposes. In all instances, the surface water must be cleaned of dispersed and dissolved solids to a level suitable for reservoir or steam-generation purposes.
Produced water typically enters the water-treatment system from either a two or three phase separator, a free water knockout, a gun barrel, a heater treater, or other primary separation unit process. It probably includes small amounts of free or dissolved hydrocarbons and solids that must be removed before the water can be re-used, injected or discharged. The level of removal (particularly for hydrocarbons) and disposal options are typically specified by state, province, or national regulations. This article discusses techniques for the removal of free and dissolved hydrocarbons. See Removing solids from water for information on solids removal. Produced water contains small concentrations (100 to 2000 mg/L) of dispersed hydrocarbons in the form of oil droplets. In applying these concepts, one must keep in mind the dispersion of large oil droplets to smaller ones and the coalescence of small droplets into larger ones, which takes place if energy is added to the system. The amount of energy added per unit time and the way in which it is added will determine whether dispersion or coalescence will take place. Stokes' law, shown in Eq. 1, is valid for the buoyant rise velocity of an oil droplet in a water-continuous phase. Several immediate conclusions can be drawn from this equation.