- Settore: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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The continuous phase of an emulsion. The internal phase is the dispersed droplets of emulsified fluid.
Industry:Oil & gas
The condition of an environment in which free oxygen is lacking or absent.
Industry:Oil & gas
The concentration of a particular substance in a living organism, possibly with harmful effects. The likelihood of this occurring is expressed as the bioaccumulation potential and can be estimated by the octanol/water partition coefficient, expressed as logP<sub>OW</sub>. This test is commonly required on drilling fluid additives in the North Sea area and other countries following the Oslo and Paris Commission (OSPAR) regulations. Values of logP<sub>OW</sub> below 3 indicate no bioaccumulation tendency; values between 3 and 6 indicate that bioaccumulation is possible, providing the substance is small enough to pass through the cell wall (mol. Wt. < 600). This may be confirmed by a bioconcentration test in which a population of animals is exposed to the product.
Industry:Oil & gas
The compound with the formula CO<sub>2</sub>. An odorless gas, carbon dioxide (CO<sub>2</sub>) is widely distributed in nature and is a minor component of air. It is highly soluble in water and oil, especially under pressure. In water, it occurs as carbonic acid, a weak acid that can donate one or two hydrogen ions in neutralization reactions that produce bicarbonate (HCO<sub>3</sub><sup>-</sup>) and carbonate (CO<sub>3</sub><sup>-2</sup>) salts or ions. CO<sub>2</sub>, being an acid in water, reacts instantly with NaOH or KOH in an alkaline water mud, forming carbonate and bicarbonate ions. Similarly, it reacts with Ca(OH)<sub>2</sub> (lime) to form insoluble calcium carbonate and water.
Industry:Oil & gas
The compound C<sub>6</sub>H<sub>5</sub>-HC=CH<sub>2</sub>, also known as styrolene, cinnamene and phenethylene. The phenyl radical, C<sub>6</sub>H<sub>5</sub><sup>-</sup>, replaces one of the hydrogen atoms on ethylene. Styrene polymers are analogous to vinyl polymers in structure except that phenyl radicals replace the corresponding H atom. (Due to larger size of the phenyl radical as compared to the H atom, not all corresponding polymers are possible. ) A phenyl radical has the benzene ring structure-missing one H-with alternating double bonds between adjacent carbons. It is an aromatic group that is nonionic.
Industry:Oil & gas
The component of a tree that is extracted in the paper-manufacturing process and used as an additive in drilling fluids. Specifically, lignin is a highly polymerized, amorphous material that makes up the middle lamella of woody fibers and cements the fibers together. Methoxy groups are abundant on the lignin structure, giving lignin many reactive sites and promoting its water solubility. In paper manufacturing, lignin is dissolved from wood chips. In the sulfite paper process, the liquor byproduct contains wood sugars and lignosulfonate. The wood sugars are removed and the lignosulfonate is used as a clay deflocculant. In the kraft paper process, lignin is solubilized by caustic soda. Kraft lignin must be further reacted to make a functional drilling-fluid additive.
Industry:Oil & gas
The complete, circuitous path that the drilling fluid travels. Starting at the main rig pumps, major components include surface piping, the standpipe, the kelly hose (rotary), the kelly, the drillpipe, drill collars, bit nozzles, the various annular geometries of the openhole and casing strings, the bell nipple, the flowline, the mud-cleaning equipment, the mud tanks, the centrifugal precharge pumps and, finally, the positive displacement main rig pumps.
Industry:Oil & gas
The complete operation of removing the drillstring from the wellbore and running it back in the hole. This operation is typically undertaken when the bit becomes dull or broken, and no longer drills the rock efficiently. After some preliminary preparations for the trip, the rig crew removes the drillstring 90 ft (27 m) at a time, by unscrewing every third drillpipe or drill collar connection. When the three joints are unscrewed from the rest of the drillstring, they are carefully stored upright in the derrick by the fingerboards at the top and careful placement on wooden planks on the rig floor. After the drillstring has been removed from the wellbore, the dull bit is unscrewed with the use of a bit breaker and quickly examined to determine why the bit dulled or failed. Depending on the failure mechanism, the crew might choose a different type of bit for the next section. If the bearings on the prior bit failed, but the cutting structures are still sharp and intact, the crew may opt for a faster drilling (less durable) cutting structure. Conversely, if the bit teeth are worn out but the bearings are still sealed and functioning, the crew should choose a bit with more durable (and less aggressive) cutting structures. Once the bit is chosen, it is screwed onto the bottom of the drill collars with the help of the bit breaker, the drill collars are run into the hole (RIH), and the drillpipe is run in the hole. Once on bottom, drilling commences again. The duration of this operation depends on the total depth of the well and the skill of the rig crew. A general estimate for a competent crew is that the round trip requires one hour per thousand feet of hole, plus an hour or two for handling collars and bits. At that rate, a round trip in a ten thousand-foot well might take twelve hours. A round trip for a 30,000-ft (9230 m) well might take 32 or more hours, especially if intermediate hole-cleaning operations must be undertaken.
Industry:Oil & gas
The company that serves as the overall manager and decision-maker of a drilling project. Generally, but not always, the operator will have the largest financial stake in the project. At the successful completion of logging the target zones, the decision to complete or plug and abandon generally has partner input and potential override clauses. As far as the drilling contractor and service companies are concerned, the designated operator is paying for the entire operation, and the operator is responsible for recouping some of that expense from the partners.
Industry:Oil & gas
The company that owns and operates a drilling rig. The drilling contractor usually charges a fixed daily rate for its hardware (the rig) and software (the people), plus certain extraordinary expenses. Under this arrangement, the cost of the well is largely a function of the time it takes to drill and complete the well. The other primary contracting methods are footage rates (where the contractor receives an agreed upon amount per foot of hole drilled), or turnkey operations, where the contractor may assume substantial risk of the operations and receives a lump sum payment upon supplying a well of a given specification to the operator.
Industry:Oil & gas
