- Branża: Oil & gas
- Number of terms: 8814
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A type of batch-treating technique used in corrosion control in which a batch of corrosion inhibitor is displaced through the tubing to the bottom of the well. The well is shut in for 2 to 15 hr and then put back on production. <br><br>The tubing-displacement technique, also called a kiss squeeze, is used mainly in wells with packers and in gas-lift wells. The treatment could last from a week to several months depending on the specific corrosion inhibitor used.
Industry:Oil & gas
A type of areally extensive reservoir that contains hydrocarbon throughout, rather than containing a water contact or being significantly affected by a water column or a defined structural closure. The areal extent of a continuous reservoir, such as a shale reservoir, can be as large as the extent of the sedimentary basin in which the shale was deposited. <br>
Industry:Oil & gas
A type of acoustic propagation along the borehole that is visualized as a shaking of the borehole across its diameter. The flexural mode is excited by a dipole source, and measured by dipole receivers oriented in the same direction. Its speed is chiefly a function of the formation shear velocity, the borehole size and fluid velocity, and the frequency. It is used to estimate formation shear velocity, and is the only technique available in slow formations where shear velocity is less than borehole-fluid velocity. In this situation, shear head waves are not generated by a monopole source, so that standard monopole techniques cannot be used. The flexural wave is sensitive to properties of the altered zone, as well as to formation anisotropy, whether intrinsic or stress-induced.
Industry:Oil & gas
A type of acoustic logging tool that uses a large number of receivers, typically 4 to 12. Modern acoustic logging tools are designed to measure not only the compressional wave but also the shear and other acoustic waves generated by the transmitter. The separation and identification of these waves are facilitated by the use of an array of receivers placed about 6 in. (15 cm) apart, which is close enough to avoid aliasing but far enough to sample a significant moveout in the wave. The waveforms at each receiver are recorded and processed by signal processing techniques, such as slowness-time coherence, to measure the velocities of the different waves.
Industry:Oil & gas
A type of acoustic energy that propagates in one direction while being confined in the other two directions, in this case by the borehole wall. Normal modes are propagated as reflections off the borehole wall, and exist only in hard rock. They are highly dispersive, starting with the formation shear velocity at a certain cutoff frequency and decreasing at high frequencies to the borehole fluid velocity. Below the cutoff frequency, they do not exist. Normal mode #0 is often considered to be the tube wave and starts at zero frequency. Normal mode #1 is called the pseudoRayleigh, and starts at around 5 kHz. The other normal modes start at increasingly higher frequencies.
Industry:Oil & gas
A type of acoustic energy that propagates in one direction while being confined in the other two directions, in this case by the borehole wall. Leaky modes can be considered as multiply reflected and constructively interfering waves propagating in the borehole. Each time a compressional wave hits the borehole wall, part of the energy is reflected into the borehole, while the rest is converted to compressional or shear energy that radiates into the formation, hence the term 'leaky'. Leaky modes are dispersive, starting at a certain cutoff frequency with the formation compressional velocity and increasing towards the borehole fluid velocity at high frequency. In slow formations, where no head wave is generated because the borehole fluid is faster than the formation compressional wave, the low-frequency end of the leaky mode can be used to determine formation compressional velocity. <br><br>The term 'hybrid mode' is used to describe a form of leaky mode that is associated with an altered zone.
Industry:Oil & gas
A type of a sucker rod-pumping unit that uses a rotor and a stator. The rotation of the rods by means of an electric motor at surface causes the fluid contained in a cavity to flow upward. It is also called a rotary positive-displacement unit.
Industry:Oil & gas
A two-phase mixture of liquid water and steam produced from a generator. The latent heat of vaporization for steam is very high, and when the steam condenses in the reservoir a significant amount of heat is transferred from the steam to the formation rock and fluids. Since steam is lighter and more mobile than oil, gravity differences and channeling of the steam through the most permeable parts of the reservoir can create sweep efficiency problems during steam-injection processes. <br><br>To increase sweep efficiency, there are two categories of improvements. The first is operational changes such as selective completion of injector wells, fracturing operations and constructing horizontal wells, and the second is the use of additives in the steam. For example, water-soluble surfactants modify interfacial properties of the oil-water system, and foams reduce steam mobility.
Industry:Oil & gas
A two-dimensional plot with one variable scaled in the vertical (Y) direction and the other in the horizontal (X) axis. The scales are usually linear but may be other functions, such as logarithmic. Additional dimensions may be represented by using color or symbols on the data points. These plots are common tools in the interpretation of petrophysical and engineering data.
Industry:Oil & gas
A two-dimensional display, using colors or different grey scales, of the holdup around the borehole versus depth. The x-axis of the image shows different segments of the borehole, normally inside a casing, displayed from the top of the hole clockwise around through the bottom and back to the top again. Depth is in the z-axis, while the values of holdup are represented by different colors or changes from black to white. <br><br>The holdup image is constructed from between four and eight local probe measurements using interpolation within constraints. Images, sometimes called maps, are also made for bubble count and bubble velocity.
Industry:Oil & gas
