In the oil industry, waterflooding or water injection is where water is injected into the oil reservoir, to maintain the pressure, or to drive oil towards the wells, and thereby increase production. Water injection wells may be located on- and offshore, to increase oil recovery from an existing reservoir.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.
Degassing, also known as degasification, is the removal of dissolved gases from liquids, especially water or aqueous solutions. There are numerous methods for removing gases from liquids.
A deaerator is a device that is used for the removal of dissolved gases like oxygen from a liquid.
A liquid-ring pump is a rotating positive-displacement gas pump, with liquid under centrifugal force acting as a seal.
A coalescer is a device which induces coalescence in a medium. They are primarily used to separate emulsions into their components via various processes, operating in reverse to an emulsifier.
Dissolved gas analysis (DGA) is an examination of electrical transformer oil contaminants. Insulating materials within electrical equipment liberate gases as they slowly break down over time. The composition and distribution of these dissolved gases are indicators of the effects of deterioration, such as pyrolysis or partial discharge, and the rate of gas generation indicates the severity. DGA is beneficial to a preventive maintenance program.
Underbalanced drilling, or UBD, is a procedure used to drill oil and gas wells where the pressure in the wellbore is kept lower than the static pressure of the formation being drilled. As the well is being drilled, formation fluid flows into the wellbore and up to the surface. This is the opposite of the usual situation, where the wellbore is kept at a pressure above the formation to prevent formation fluid entering the well. In such a conventional "overbalanced" well, the invasion of fluid is considered a kick, and if the well is not shut-in it can lead to a blowout, a dangerous situation. In underbalanced drilling, however, there is a "rotating head" at the surface - essentially a seal that diverts produced fluids to a separator while allowing the drill string to continue rotating.
An oil production plant is a facility which processes production fluids from oil wells in order to separate out key components and prepare them for export. Typical oil well production fluids are a mixture of oil, gas and produced water. An oil production plant is distinct from an oil depot, which does not have processing facilities.
The term separator in oilfield terminology designates a pressure vessel used for separating well fluids produced from oil and gas wells into gaseous and liquid components. A separator for petroleum production is a large vessel designed to separate production fluids into their constituent components of oil, gas and water. A separating vessel may be referred to in the following ways: Oil and gas separator, Separator, Stage separator, Trap, Knockout vessel, Flash chamber, Expansion separator or expansion vessel, Scrubber, Filter. These separating vessels are normally used on a producing lease or platform near the wellhead, manifold, or tank battery to separate fluids produced from oil and gas wells into oil and gas or liquid and gas. An oil and gas separator generally includes the following essential components and features:
- A vessel that includes (a) primary separation device and/or section, (b) secondary "gravity" settling (separating) section, (c) mist extractor to remove small liquid particles from the gas, (d) gas outlet, (e) liquid settling (separating) section to remove gas or vapor from oil, (f) oil outlet, and (g) water outlet.
- Adequate volumetric liquid capacity to handle liquid surges (slugs) from the wells and/or flowlines.
- Adequate vessel diameter and height or length to allow most of the liquid to separate from the gas so that the mist extractor will not be flooded.
- A means of controlling an oil level in the separator, which usually includes a liquid-level controller and a diaphragm motor valve on the oil outlet.
- A back pressure valve on the gas outlet to maintain a steady pressure in the vessel.
- Pressure relief devices.
In chemistry, sparging, also known as gas flushing in metallurgy, is a technique in which a gas is bubbled through a liquid in order to remove other dissolved gas(es) and/or dissolved volatile liquid(s) from that liquid. It is a method of degassing. According to Henry's law, the concentration of each gas in a liquid is proportional to the partial pressure of that gas in contact with the liquid. Sparging introduces a gas that has little or no partial pressure of the gas(es) to be removed, and increases the area of the gas-liquid interface, which encourages some of the dissolved gas(es) to diffuse into the sparging gas before the sparging gas escapes from the liquid. Many sparging processes, such as solvent removal, use air as the sparging gas. To remove oxygen, or for sensitive solutions or reactive molten metals, a chemically inert gas such as nitrogen, argon, or helium is used.
In chemical engineering, a vapor–liquid separator is a device used to separate a vapor–liquid mixture into its constituent phases. It can be a vertical or horizontal vessel, and can act as a 2-phase or 3-phase separator.
Produced water is a term used in the oil industry or geothermal industry to describe water that is produced as a byproduct during the extraction of oil and natural gas, or used as a medium for heat extraction. Water that is produced along with the hydrocarbons is generally brackish and saline water in nature. Oil and gas reservoirs often have water as well as hydrocarbons, sometimes in a zone that lies under the hydrocarbons, and sometimes in the same zone with the oil and gas. In geothermal plants, the produced water is usually hot. It contains steam with dissolved solutes and gases, providing important information on the geological, chemical, and hydrological characteristics of geothermal systems. Oil wells sometimes produce large volumes of water with the oil, while gas wells tend to produce water in smaller proportions.
Groundwater remediation is the process that is used to treat polluted groundwater by removing the pollutants or converting them into harmless products. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. Globally, between 25 per cent and 40 per cent of the world's drinking water is drawn from boreholes and dug wells. Groundwater is also used by farmers to irrigate crops and by industries to produce everyday goods. Most groundwater is clean, but groundwater can become polluted, or contaminated as a result of human activities or as a result of natural conditions.
Desanders and desilters are solid control equipment with a set of hydrocyclones that separate sand and silt from the drilling fluids in drilling rigs. Desanders are installed on top of the mud tank following the shale shaker and the degasser, but before the desilter. The desander removes the abrasive solids from the drilling fluids which cannot be removed by shakers. Normally, the solid diameters for desanders to separate would be 45~74μm, and 15~44μm for desilters.
A defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. The terms anti-foam agent and defoamer are often used interchangeably. Strictly speaking, defoamers eliminate existing foam and anti-foamers prevent the formation of further foam. Commonly used agents are insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols. The additive is used to prevent formation of foam or is added to break a foam already formed.
Effective solids control can be attributed to the overall performance of all the components of the mud systems. Conditioning the drilling fluid with the goal of dramatically lowering maintenance cost, avoiding excessive chemical treatment and maintaining mud systems volume will decrease the chance of equipment failure, unnecessary high mud costs, hole and drilling problems.
Mud Gas Separator is commonly called a gas-buster or poor boy degasser. It captures and separates the large volumes of free gas within the drilling fluid. If there is a "kick" situation, this vessel separates the mud and the gas by allowing it to flow over baffle plates. The gas then is forced to flow through a line, venting to a flare. A "kick" situation happens when the annular hydrostatic pressure in a drilling well temporarily falls below that of the formation, or pore, pressure in a permeable section downhole, and before control of the situation is lost.
Dissolved gas flotation (DGF) systems are used for a variety of applications throughout the world. The process floats solids, oils and other contaminants to the surface of liquids. Once on the surface these contaminants are skimmed off and removed from the liquids. Oil and gas production facilities have used flotation systems to remove oil and solids from their produced and processed water (wastewater) for many years. The relative density of candle wax is 0.93, hence objects made of wax float on water.
An oil water separator (OWS) is a piece of equipment used to separate oil and water mixtures into their separate components. There are many different types of oil-water separator. Each has different oil separation capability and are used in different industries. Oil water separators are designed and selected after consideration of oil separation performance parameters and life cycle cost considerations. "Oil" can be taken to mean mineral, vegetable and animal oils, and the many different hydrocarbons.