- Industry: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
Solids added to a drilling fluid to bridge across the pore throat or fractures of an exposed rock thereby building a filter cake to prevent loss of whole mud or excessive filtrate. Bridging materials are commonly used in drilling fluids and in lost circulation treatments. For reservoir applications, the bridging agent should be removable-common products include calcium carbonate (acid-soluble), suspended salt (water-soluble) or oil-soluble resins. For lost-circulation treatments, any suitably sized products can be used, including mica, nutshells and fibers. These products are more commonly referred to as lost-circulation material (LCM).
Industry:Oil & gas
Solid particles of size less than 2 microns equivalent spherical diameter, also identified as clay by definitions in International Standards Organization ISO/CD 13501, par. 3. 1. 17. Because of extremely small size, these solids largely defy direct removal by mechanical devices that rely on screening or gravitational forces. Their removal is aided by chemical aggregation prior to gravity separation or filtration.
Industry:Oil & gas
Solid material intentionally introduced into a mud system to reduce and eventually prevent the flow of drilling fluid into a weak, fractured or vugular formation. This material is generally fibrous or plate-like in nature, as suppliers attempt to design slurries that will efficiently bridge over and seal loss zones. In addition, popular lost circulation materials are low-cost waste products from the food processing or chemical manufacturing industries. Examples of lost circulation material include ground peanut shells, mica, cellophane, walnut shells, calcium carbonate, plant fibers, cottonseed hulls, ground rubber, and polymeric materials.
Industry:Oil & gas
Small pieces of rock that break away due to the action of the bit teeth. Cuttings are screened out of the liquid mud system at the shale shakers and are monitored for composition, size, shape, color, texture, hydrocarbon content and other properties by the mud engineer, the mud logger and other on-site personnel. The mud logger usually captures samples of cuttings for subsequent analysis and archiving.
Industry:Oil & gas
Settling of particles in the annulus of a well, which can occur when the mud is static or being circulated. Because of the combination of secondary flow and gravitational forces, weighting materials can settle (sag) in a flowing mud in a high-angle well. If settling is prolonged, the upper part of a wellbore will lose mud density, which lessens the hydrostatic pressure in the hole, so an influx (a kick) of formation fluid can enter the well.
Industry:Oil & gas
Relating to two or more logging measurements that have the same response. The term normally refers to vertical resolution, but could also be used for azimuthal or radial resolution. The term implies that all the features of the vertical response are matched, ideally in all conditions. In practice, it is used to describe a more detailed matching of the vertical response than with resolution-matched curves.
Industry:Oil & gas
Slang for penetration rate, or the speed that the bit is drilling into the formation.
Industry:Oil & gas
