Oil and Gas Terms Beginning with “P” — Page 7

A fluid-loss control additive used in high-temperature, water-base muds. It shows good salt tolerance and temperature tolerance. Read more →

A series of alcohols with glycerol, C3H5(OH)3, (usually referred to as glycerin in the USA) being the simplest member. Polyglycerols have been used as shale inhibitors in water-base drilling fluids. Read more →

A large molecule made up of repeating units. Some polymers are naturally occurring, such as xanthan gum, guar gum and starch. Other polymers are modified natural polymers, such as carboxymethylcellulose (CMC) and… Read more →

What Is Polymer Flooding? Polymer flooding is an enhanced oil recovery (EOR) method in which water-soluble polymer — typically partially hydrolysed polyacrylamide (HPAM) or xanthan biopolymer — is dissolved in the… Read more →

A volume of polymerslurry placed in a wellbore, which, in time and under the correct temperature conditions, will develop to provide a high-viscosity platform on which a cement plug can be placed. Polymer plugs are… Read more →

A generic name for low molecular weight, water-soluble polymers and oligomers containing a large number of hydroxyl groups. Specific examples include glycols, polyglycols and polyglycerols. Polyols are used in… Read more →

A carbohydrate composed of many monosaccharides. Polysaccharides increase the viscosity of the water slug that precedes the final water injection. However, they are not frequently used in chemical flooding operations… Read more →

A rod shorter than usual, usually placed below the polished rod and used to make a rod string of a desired length. Read more →

The accumulation of smaller tracts of land, the sum total acreage of which are required for a governmental agency to grant a well permit or assign a production quota or allowable to an operator. Read more →

A type of check valve often used in the lines or manifolds associated with kill and choke lines or pressure-control equipment. Read more →

A discrete void within a rock, which can contain air, water, hydrocarbons or other fluids. In a body of rock, the percentage of pore space is the porosity. Read more →

What Is Pore Pressure? Pore pressure (also called formation pressure or reservoir pressure) is the pressure of the fluid contained in the pore space of a rock formation. At hydrostatic conditions (normal pore pressure),… Read more →

In an intergranular rock, the small pore space at the point where two grains meet, which connects two larger pore volumes. The number, size and distribution of the pore throats control many of the resistivity, flow and… Read more →

The pressure of the subsurface formation fluids, commonly expressed as the density of fluid required in the wellbore to balance that pore pressure. A normal gradient might require 9 lbm/gal [1.08 kg/m3], while an… Read more →

A laboratory test used to determine if a drilling fluid blocks movement of filtrate through pore spaces of a shale sample. The PPT device monitors the increase in pore pressure in a shale when exposed to a drilling… Read more →

An instrument for measuring the pore volume, and hence the porosity, of a core sample. The term is also used for some instruments that actually measure grain volume, such as the Boyle?s Law Double-Cell method. Pore… Read more →

What Is Porosity? Porosity measures the fraction of a rock's bulk volume occupied by void spaces, expressed as a decimal or percentage, and directly controls how much fluid a reservoir can store. Petrophysicists and… Read more →

What Is the Porosity Exponent? The porosity exponent (m), also called the cementation exponent or cementation factor, is a dimensionless parameter in Archie's Law (F = a / φ^m) that describes how the electrical… Read more →

A unit equal to the percentage of pore space in a unit volume of rock. It is abbreviated to p.u. and lies between 0 and 100. Read more →

A rock or soil with interconnected pores that permit flow of fluids through the medium. Read more →

A method for desaturating a core sample by placing one end in capillary contact with a porous plate and applying gas or oil under pressure to the remaining surfaces. The liquid in the original fully saturated sample is… Read more →

The product obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates. Portland cement is the most common type of cement used for oil- and gas-well cementing. Read more →

Hard granular nodules composed essentially of hydraulic calcium silicates, with smaller quantities of calcium aluminates and ferrites. Portland cement clinker is produced by the heat treatment of cement raw materials in… Read more →

A type of fluid pump in which the displacement volume of the pump is fixed for each rotation of the pump. Generally associated with high-pressure applications, positive-displacement pumps are commonly used in drilling… Read more →

To annotate a map or other display with data at the appropriate location. For example, geologists post formation tops on well logs, isopach maps and seismic profiles. Geophysicists post velocity values and traveltimes… Read more →

Pertaining to a hydrocarbon source rock that has generated as much hydrocarbon as possible and is becoming thermally altered. Read more →

An element with an atomic number of 19. The 40K isotope is radioactive, decaying with the emission of a single gamma ray of 1.46 MeV with a half-life of 1.3 * 109 years to give a stable isotope of argon. Potassium is… Read more →

The ion of potassium, K+. There are tests used to monitor high (>5000 mg/L) or low ( Read more →

A class of muds that contain potassium ion (K+) dissolved in the water phase. Potassium muds are the most widely accepted water mud system for drilling water-sensitive shales, especially hard, brittle shales. K+ ions… Read more →

A field that satisfies the Laplace equation. The Laplace equation is equivalent in three dimensions to the inverse square law of gravitational or electrical attraction (in source-free regions; in regions with sources,… Read more →