- Industry: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
An agreement between the operator and net revenue interest (NRI) owner in which the parties specify the fractional type of interest attributed to the NRI owner by the operator after an examination of title.
Industry:Oil & gas
An additive, generally in slurry or liquid form, used to reduce the friction forces experienced by tools and tubulars in the wellbore. Friction reducers are routinely used in horizontal and highly deviated wellbores where the friction forces limit the passage of tools along the wellbore.
Industry:Oil & gas
An advanced testing technique using a combination of transient-rate and pressure measurements and stabilized flow profiles to determine permeability and skin for each of several layers commingled in a well. The technique requires a series of flow-rate changes, with at least one flow-rate change for each layer to be characterized.
Industry:Oil & gas
An agreement between a host country and operator to allow the operator to evaluate geological, geophysical, engineering and transportation issues involving a concession. Also known as a TEA.
Industry:Oil & gas
An acoustic device that measures the time required for an explosive sound to echo from the annular liquid level in nonflowing wells. The time is proportional to the distance from the surface to the liquid. It is used to determine backpressure in the formation or a static fluid level in the annulus. It is also known as an echo meter.
Industry:Oil & gas
An acid treatment placed in the wellbore over the interval to be perforated. Because of the overbalance conditions at the time of perforating, the perforating acid is forced into the newly formed perforation tunnel to stimulate the crushed zone. Formulation of the perforating acid depends on the characteristics of the formation and the downhole equipment used.
Industry:Oil & gas
An acid type commonly used in oil- and gas- well stimulation, especially in carbonate formations. The reaction characteristics of hydrochloric acid enable it to be used in a wide range of treatments, often with chemical additives that enhance its performance or allow greater control of the treatment. Treatments are most commonly conducted with 15% or 28% solutions of hydrochloric acid.
Industry:Oil & gas
An acid treatment fluid that has been mixed with chemical additives to control the corrosive effect on the mixing and pumping equipment, as well as on any wellbore tubulars and completion equipment that the fluid may contact. Almost all acid treatments require the addition of an inhibitor to protect against undesirable reactions.
Industry:Oil & gas
An acid mixture that generates more hydrofluoric (HF) acid as the HF is consumed. In the field, fluoboric acid (HBF<sub>4</sub>) is easily prepared by mixing boric acid (H<sub>3</sub>BO<sub>3</sub>), ammonium bifluoride (NH<sub>3</sub>F. HF) and hydrochloric acid. Fluoboric acid was developed to counteract the shortcomings associated with mud-acid treatments. It is a retarded fluid that can penetrate deep into the reservoir before spending, especially at high temperatures, and does not contain high HF at any given time. Thus, it is less reactive than mud acid, but its total dissolving power is comparable:<br><br>HBF<sub>4</sub> + H<sub>3</sub>O --> HBF<sub>3</sub>OH + HF. <br><br>The limited amount of HF at any given time decreases the probability of forming precipitates of fluosilicates, fluoaluminates or silica. Fluoboric acid provides permanent stabilization of clays and fines through reactions related to borate and fluoborate ions. For example, borosilicates coat and bind undissolved clays and fines, preventing further mobility of these particles that might plug the formation and impair production. Mud acid does not provide this coating feature. Fluoboric acid also eliminates water sensitivity and is especially recommended in formations containing potassium minerals. <br><br>Fluoboric acid can be used as a preflush, an overflush or as a main stage in a sandstone matrix acidizing. As a main fluid, a fluoboric acid treatment requires a preflush (weak HCl acid or brine) and should not be overflushed to obtain the maximum stabilization effect in the critical matrix area. Fluoboric acid treatments are the only acid formulations that require long shut-in times because of their long reaction times.
Industry:Oil & gas
Aerobic bacteria that convert iron from the ferrous (Fe<sup>+2</sup>) to the ferric (Fe<sup>+3</sup>) state and produce ferric hydroxide (Fe(OH)<sub>3</sub>), which is a highly insoluble by-product that will damage the formation. Iron-oxidizing bacteria also produce some corrosion, but they are considered harmful mainly because they cover sulfate-reducing bacteria colonies and protect them from attack with bactericides.
Industry:Oil & gas
