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At low pressures and relatively high temperatures, the volume of most gases is so large that the volume of the molecules themselves may be neglected. Also, the distance between molecules is so great that the presence of even fairly strong attractive or repulsive forces is not sufficient to affect the behavior in the gas state. However, as the pressure is increased, the total volume occupied by the gas becomes small enough that the volume of the molecules themselves is appreciable and must be considered. Also, under these conditions, the distance between the molecules is decreased to the point at which the attractive or repulsive forces between the molecules become important. This behavior negates the assumptions required for ideal gas behavior, and serious errors are observed when comparing experimental volumes to those calculated with the ideal gas law.
Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide H2S).Sour gas reserves are historically left undeveloped because of the technical challenges and costs involved in their extraction and processing. Natural gas that contains more than 4 ppmv of hydrogen sulphide (H2S) is commonly referred to as "sour". This is because the odour of hydrogen sulphide gas in air at very low concentrations is similar to that of rotten eggs. Significant quantities of natural gas resources around the world are known to contain H2S. These have been difficult to produce in the past because of the tendency for sour gas to cause corrosion and sulphide stress corrosion cracking, particularly in pipelines.
In a perspective piece that appears in the journal Science, Elaine Hill, an economist in the University of Rochester Medical Center Department of Public Health Sciences, calls for tighter regulation and monitoring of unconventional oil and gas development as more evidence points to the negative health consequences of the practice. The debate over hydraulic fracturing often is viewed through either an economic lens that emphasizes jobs and energy independence or an environmental one that warns of the damage to air and water quality and human health. Because fracturing technology has been operating on a significant scale in the US for the past 2 decades, the scope of the public health impact from long-term exposure to air, water, and noise pollution is only now becoming clear. The rising toll in the form of increased rates of chronic diseases, stress on rural healthcare providers, and growing need for mental health and addiction services ultimately diminishes the economic returns for communities that host the hydraulic fracturing industry. "Many of the impacts have lifelong consequences on individual wellbeing, including future health, education, and labor market outcomes," said Hill and coauthor Lala Ma, with the Department of Economics at the University of Kentucky.
The oil and gas industry is becoming more technologically advanced every day. As automation, artificial intelligence (AI) and robotics improve, it may be increasingly tempting to employ automatic means to accomplish industry goals. The degree to which a task is automated is referred to as levels of automation (LOA). The most comprehensive list was developed by Thomas B. Sheridan and W. L. Verplank. Levels of automation range from complete human control to complete computer control.
Molecules of a particular chemical species are composed of groups of atoms that always combine according to a specific formula. The chemical formula and the international atomic weight table provide us with a scale for determining the weight ratios of all atoms combined in any molecule. The molecular weight, M, of a molecule is simply the sum of all the atomic weights of its constituent atoms. It follows, then, that the number of molecules in a given mass of material is inversely proportional to its molecular weight. Therefore, when masses of different materials have the same ratio as their molecular weights, the number of molecules present is equal.
Hydrogen sulfide (H2S) is highly toxic, with a distinctive "rotten eggs" odor. If the formation oil or gas is sour, there is no alternative but to produce the H2S and, because it generally has minimal economic value, dispose of the gas in a safe and cost-effective manner. The treatment procedure and treatment location depend on the concentration of H2S. Caustic scrubbing can be used for the removal of high concentrations. Treatment of the low-concentration H2S (nominally 150 ppm) is made using nonregenerative chemical technology that is more efficient at low H2S concentrations.
Sour natural gas compositions can vary over a wide concentration of H2S and CO2 and a wide concentration of hydrocarbon components. If the H2S content exceeds the sales gas specification limit, the excess H2S must be separated from the sour gas. The removal of H2S from sour gas is called "sweetening." The selected process must be cost effective in meeting the various specifications and requirements. Throughout the world, regulations generally limit the flaring of H2S. Sweetening of gas streams containing very low concentrations of H2S can be done in many ways, depending on the general conditions. If the sour gas stream contains more than 70 to 100 pounds of sulfur/day in the form of H2S in the inlet gas to a sour plant, a regenerative chemical solvent is usually selected for the sweetening of the sour gas stream. For very low H2S content sour gas, a scavenger chemical is usually used. In such cases, the chemical is consumed, and the method for ultimate disposal of the spent chemical is a consideration.
Natural gas is a mixture of many compounds, with methane (CH4) being the main hydrocarbon constituent. When natural gas is produced from an underground reservoir, it is saturated with water vapor and might contain heavy hydrocarbon compounds as well as nonhydrocarbon impurities. In the raw state, natural gas cannot be marketed and therefore must be processed to meet certain specifications for sales gas. Additionally, it might be economical to extract liquefiable hydrocarbon components, which would have a higher market value on extraction as compared with their heating value if left in the gas. Gas treating facilities, therefore, must be designed to convert a particular raw gas mixture into a sales gas that meets the sales-gas specifications, and such facilities must operate without interruption.
Project management costs must be considered in the authority for expenditure (AFE). These charges include well supervision and administration. Large costs can be incurred for deep wells or problem wells, such as those that encounter H2S. Supervision includes direct management of the well, including the on-site supervisor and any members of the office staff who are dedicated to the project. Mud or completion consultants may be considered as supervision.