- Branża: Oil & gas
- Number of terms: 8814
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A rounded profile component attached to the downhole end of a casing string. An integral check valve in the float shoe prevents reverse flow, or U-tubing, of cement slurry from the annulus into the casing or flow of wellbore fluids into the casing string as it is run. The float shoe also guides the casing toward the center of the hole to minimize hitting rock ledges or washouts as the casing is run into the wellbore. The float shoe reduces hook weight. With controlled or partial fill-up as the string is run, the casing string can be floated into position, avoiding the need for the rig to carry the entire weight of the casing string. The outer portions of the float shoe are made of steel and generally match the casing size and threads, although not necessarily the casing grade. The inside (including the taper) is usually made of cement or thermoplastic, since this material must be drilled out if the well is to be deepened beyond the casing point.
Industry:Oil & gas
A rubber plug used to separate the cement slurry from other fluids, reducing contamination and maintaining predictable slurry performance. Two types of cementing plug are typically used on a cementing operation. The bottom plug is launched ahead of the cement slurry to minimize contamination by fluids inside the casing prior to cementing. A diaphragm in the plug body ruptures to allow the cement slurry to pass through after the plug reaches the landing collar. The top plug has a solid body that provides positive indication of contact with the landing collar and bottom plug through an increase in pump pressure.
Industry:Oil & gas
A rod shorter than usual, usually placed below the polished rod and used to make a rod string of a desired length.
Industry:Oil & gas
A rock volume with identifiable fluid flow characteristics that can be modeled, including heterogeneity or anisotropy.
Industry:Oil & gas
A rock whose petrophysical properties are well described by the Archie equation with constant values for the porosity exponent and the saturation exponent. Such rocks typically have very little clay, a regular pore structure and high-salinity water. The term often is used to describe a rock that is petrophysically simple.
Industry:Oil & gas
A rock characterized by primary porosity from original deposition and secondary porosity from some other mechanism, and in which all flow to the well effectively occurs in one porosity system, and most of the fluid is stored in the other. Naturally fractured reservoirs and vugular carbonates are classified as dual-porosity reservoirs, as are layered reservoirs with extreme contrasts between high-permeability and low-permeability layers.
Industry:Oil & gas
A rock or soil with interconnected pores that permit flow of fluids through the medium.
Industry:Oil & gas
A rock rich in organic matter which, if heated sufficiently, will generate oil or gas. Typical source rocks, usually shales or limestones, contain about 1% organic matter and at least 0. 5% total organic carbon (TOC), although a rich source rock might have as much as 10% organic matter. Rocks of marine origin tend to be oil-prone, whereas terrestrial source rocks (such as coal) tend to be gas-prone. Preservation of organic matter without degradation is critical to creating a good source rock, and necessary for a complete petroleum system. Under the right conditions, source rocks may also be reservoir rocks, as in the case of shale gas reservoirs.
Industry:Oil & gas
A rise in well pressure as a function of time observed after a well is shut in or after the production rate is reduced. Buildup pressures are normally measured at or near the bottom of the hole.
Industry:Oil & gas
A resistivity recorded by a measurements-while-drilling propagation tool consisting of an array of transmitters and receivers whose signals are recorded separately and combined by software to produce the response desired. In a typical design, five transmitters emit a signal, and the phase shift and attenuation between two receivers are recorded. The phase shifts and attenuations are combined in different ways to produce borehole-compensated logs with different depths of investigation and radial resolution.
Industry:Oil & gas
