Accredited Investor:
 Any natural person whose individual net worth, or joint net worth with that person’s spouse, at the time of his purchase exceeds $1,000,000. Or any natural person who had individual income in excess of $200,000 in each of the two most recent years or joint income with that person’s spouse in excess of $300,000 in each of those years and has a reasonable expectation of reaching the same income level in the current year.

Beneficiary:
 A person or entity named in a will or a financial contract as the inheritor of property when the property owner dies. A beneficiary can be a spouse, child, charity or any entity or person to whom the property owner would like to leave his or her possessions and assets.

Contract:
 A legal agreement between entities that requires each to conduct (or refrain from conducting) certain activities. This document provides each party with a right that is enforceable under our judicial system.

Daily Drilling report:
 A record made each day of the operations on a working drilling rig and, traditionally, phoned, faxed, emailed, or radioed in to the office of the drilling company and possibly the operator every morning.

Dampener:
 An air or inert gas device that minimizes pressure surges in the output line of a mud pump. Sometimes called a surge dampener.

Day Tour:
 (pronounced "tower") In areas where two 12-hour tours are worked, a period of 12 hours, usually during daylight, worked by a drilling or workover crew when equipment is being run around the clock.

Daylight Tour:
 (pronounced "tower") In areas where three eight-hour tours are worked, the shift of duty on a drilling rig that starts at or about daylight. Compare evening tour, morning (graveyard) tour.

Deadline:
 The drilling line from the crown block sheave to the anchor, so called because it does not move. Compare fast line.

Deadline Anchor:
 See deadline tie-down anchor.

Deadline Sheave:
 The sheave on the crown block over which the deadline is reeved.

Deadline Tie-Down Anchor:
 A device to which the deadline is attached, securely fastened to the mast or derrick substructure. Also called a deadline anchor.

Deck:
 Floor.

Degasser:
 The equipment used to remove unwanted gas from a liquid, especially from drilling fluid.

Density:
 The mass or weight of a substance per unit volume. For instance, the density of a drilling mud may be 10 pounds per gallon, 74.8 pounds/cubic foot, or 1,198.2 kilograms/cubic meter. Specific gravity, relative density, and API gravity are other units of density.

Density Log:
 A special radioactivity log for open-hole surveying that responds to variations in the specific gravity of formations. It is a contact log (i.e., the logging tool is held against the wall of the hole). It emits neutrons and then measures the secondary gamma radiation that is scattered back to the detector in the instrument. The density log is an excellent porosity-measure device, especially for shaley sands. Some trade names are Formation Density Log, Gamma-Gamma Density Log, and Densilog.

Derrick:
 A large load-bearing structure, usually of bolted construction. In drilling, the standard derrick has four legs standing at the corners of the substructure and reaching to the crown block. The substructure is an assembly of heavy beams used to elevate the derrick and provide space to install blowout preventers, casingheads, and so forth.

Derrick Floor:
 Also called the rig floor.

Derrickhand:
 The crew member who handles the upper end of the drill string as it is being hoisted out of or lowered into the hole. On a drilling rig, he or she may be responsible for the circulating machinery and the conditioning of the drilling or workover fluid.

Derrickman:
 See derrickhand.

Desander:
 A centrifugal device for removing sand from drilling fluid to prevent abrasion of the pumps. It may be operated mechanically or by a fast-moving stream of fluid inside a special cone-shaped vessel, in which case it is sometimes called a hydrocyclone.

Desilter:
 A centrifugal device, similar to a desander, used to remove very fine particles, or silt, from drilling fluid to lower the amount of solids in the fluid.

Diamond Bit:
 A drill bit that has small industrial diamonds embedded in its cutting surface.

Die Insert:
 A removable, hard-steel, serrated piece that fits into the jaws of the tongs and firmly grips the body of the drill pipe, drill collars, or casing while the tongs are making up or breaking out the pipe.

Dies:
 A tool used to shape, form, or finish other tools or pieces of metal. For example, a threading die is used to cut threads on pipe.

Diesel Engine:
 A high-compression, internal-combustion engine used extensively for powering drilling rigs. In a diesel engine, air is drawn into the cylinders and compressed to very high pressures; ignition occurs as fuel is injected into the compressed and heated air. Combustion takes place within the cylinder above the piston, and expansion of the combustion products imparts power to the piston.

Diesel Fuel:
 A light hydrocarbon mixture for diesel engines; it has a boiling range just above that of kerosene.

Diesel-Electric Power:
 The power supplied to a drilling rig by diesel engines driving electric generators.

Dipmeter Log:
 See dipmeter survey.

Dipmeter Survey:
 An oilwell-surveying method that determines the direction and angle of formation dip in relation to the borehole. It records data that permit computation of both the amount and direction of formation dip relative to the axis of the hole and thus provides information about the geologic structure of the formation. Also called dipmeter log or dip log.

Directional Drilling:
 Intentional deviation of a wellbore from the vertical. Although wellbores are normally drilled vertically, it is sometimes necessary or advantageous to drill at an angle from the vertical. Controlled directional drilling makes it possible to reach subsurface areas laterally remote from the point where the bit enters the earth.

Directional Hole:
 A wellbore intentionally drilled at an angle from the vertical. See directional drilling.

Displacement Fluid:
 In well cementing, the fluid, usually drilling mud or salt water, that is pumped into the well after the cement is pumped into it to force the cement out of the casing and into the annulus.

Dissolved Gas:
 Natural gas that is in solution with crude oil in the reservoir.

Dissolved-Gas Drive:
 A source of natural reservoir energy in which the dissolved gas coming out of the oil expands to force the oil into the wellbore. Also called solution-gas drive. See reservoir drive mechanism.

Doghouse:
 A small enclosure on the rig floor used as an office and/or as a storehouse for small objects. Also, any small building used as an office or for storage.

Dogleg:
 1. An abrupt change in direction in the wellbore, frequently resulting in the formation of a keyseat. 2. A sharp bend permanently put in an object such as a pipe, wire rope, or a wire rope sling.

Double:
 A length of drill pipe, casing, or tubing consisting of two joints screwed together.

Downhole Motor:
 A drilling tool made up in the drill string directly above the bit. It causes the bit to turn while the drill string remains fixed. It is used most often as a deflection tool in directional drilling, where it is made up between the bit and a bent sub (or, sometimes, the housing of the motor itself is bent). Two principal types of downhole motor are the positive-displacement motor and the downhole turbine motor.

Drawworks:
 The hoisting mechanism on a drilling rig. It is essentially a large winch that spools off or takes in the drilling line and thus lowers or raises the drill stem and bit.

Drawworks Brake:
 The mechanical brake on the drawworks that can slow or prevent the drawworks drum from moving.

Drawworks Drum:
 The spool-shaped cylinder in the drawworks around which drilling line is wound or spooled.

Drill:
 To bore a hole in the earth, usually to find and remove subsurface formation fluids such as oil and gas.

Drill Ahead:
 To continue drilling operations.

Drill Bit:
 The cutting or boring element used in drilling oil and gas wells. Most bits used in rotary drilling are roller-cone bits. The bit consists of the cutting elements and the circulating element. The circulating element permits the passage of drilling fluid and utilizes the hydraulic force of the fluid stream to improve drilling rates.

Drill Collar Sub:
 A sub made up between the drill string and the drill collars that is used to ensure that the drill pipe and the collar can be joined properly.

Drill Collars:
 A heavy, thick-walled tube, usually steel, used between the drill pipe and the bit in the drill stem, used to stiffen the drilling assembly an put weight on the bit so that the bit can drill.

Drill Floor:
 Also called rig floor or derrick floor. See rig floor.

Drill In:
 To penetrate the productive formation after the casing is set and cemented on top of the pay zone.

Drill Pipe:
 The heavy seamless tubing used to rotate the bit and circulate the drilling fluid. Joints of pipe are generally approximately 30 feet long are coupled together by means of tool joints.

Drill Stem:
 All members in the assembly used for rotary drilling from the swivel to the bit, including the kelly, the drill pipe and tool joints, the drill collars, the stabilizers, and various specialty items. Compare drill string.

Drill Stem Test (DST):
 A method of formation testing. The basic drill stem test tool consists of a packer or packers, valves or ports that may be opened and closed from the surface, and two or more pressure-recording devices. The tool is lowered on the drill string to the zone to be tested. The packer or packers are set to isolate the zone from the drilling fluid column.

Drill String:
 The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and the bit. Often, the term is loosely applied to include both drill pipe and drill collars.

Drillable:
 Pertaining to packers and other tools left in the wellbore to be broken up later by the drill bit. Drillable equipment is made of cast iron, aluminum, plastic, or other soft, brittle material.

Drillable Packer:
 A permanent packer that can only be removed by drilling it out.

Driller:
 The employee normally in charge of a specific (tour) drilling or workover crew. The driller’s main duty is operation of the drilling and hoisting equipment, but this person may also be responsible for downhole condition of the well, operation of downhole tools, and pipe measurements.

Driller`s Console:
 The control panel, where the driller controls drilling operations.

Driller’s Position:
 The area immediately surrounding the driller’s console.

Drilling Contract:
 An agreement made between a drilling company and an operating company to drill a well. It generally sets forth the obligation of each party, compensation, identification, method of drilling, depth to be drilled, and so on.

Drilling Crew:
 A driller, a derrickhand, and two or more helpers who operate a drilling or workover rig for one tour each day.

Drilling Engine:
 An internal-combustion engine used to power a drilling rig. These engines are used on a rotary rig and are usually fueled by diesel fuel, although liquefied petroleum gas, natural gas, and, very rarely, gasoline can also be used.

Drilling Engineer:
 An engineer who specializes in the technical aspects of drilling.

Drilling Fluid:
 Circulating fluid, one function of which is to lift cuttings out of the wellbore and to the surface. It also serves to cool the bit and to counteract downhole formation pressure.

Drilling Hook:
 The large hook mounted on the bottom of the traveling block and from which the swivel is suspended.

Drilling Line:
 A wire rope hoisting line, reeved on sheaves of the crown block and traveling block (in effect a block and tackle), the primary purpose of which is to hoist or lower drill pipe or casing from or into a well.

Drilling Mud:
 A specially compounded liquid circulated through the wellbore during rotary drilling operations. See drilling fluid, mud.

Drilling Out:
 The operation during the drilling procedure when the cement is drilled out of the casing.

Drive Bushing:
 See kelly bushing.

Drive Chain:
 A chain by means of which a machine is propelled.

Drive Pipe:
 See conductor casing.

Drive-in Unit:
 A type of portable service or workover rig that is self-propelled, using power from the hoisting engines. The driver’s cab and steering wheel are mounted on the same end as the mast support; thus the unit can be driven straight ahead to reach the wellhead.

Drum (rope):
 A rotating cylinder with side flanges on which wire or other rope used in machine operation is wrapped.

Dual Completion:
 A single well that produces from two separate formations at the same time. Production from each zone is segregated by running two tubing strings with packers inside the single string of production casing, or by running one tubing string with a packer through one zone while the other is produced through the annulus. In a miniaturized dual completion, two separate casing strings are run and cemented in the same wellbore.

Due Diligence:
 The process of gathering information about the condition and legal status of assets to be sold.

Dump Bailer:
 A bailing device with a release valve, usually of the disk or flapper type, used to place, or spot, material (such as cement slurry) at the bottom of the well.

Income:
 For corporations, revenues minus cost of sales, operating expenses, and taxes, over a given period of time. Income is the reason corporations exist, and are often the single most important determinant of a stock's price. Income is important to investors because they give an indication of the company's expected futuredividends and its potential for growth and capital appreciation. That does not necessarily mean that low or negative earnings always indicate a bad stock; for example, many young companies report negative income as they attempt to grow quickly enough to capture a new market, at which point they'll be even more profitable than they otherwise might have been. also called earnings.

Loss:
 A reduction in the value of an investment.

A condition in which a company's expenses exceed its revenues. Opposite of profit.

Net Income:
 In business, what remains after subtracting all the costs (namely, business, depreciation, interest, and taxes) from a company’s revenues. Net income is sometimes called the bottom line. Also called earnings or net profit.

For an individual, gross income minus taxes, allowances, and deductions. An individual's net income is used to determine how much income tax is owed.

Non-Accredited Investors:
 Persons or entities who do not satisfy one or more of the alternative definitions of the term "Accredited Investor" and who, by virtue of their financial resources acumen, satisfy a joint venture manager or its authorized representatives that such investors satisfy the suitability standards imposed by Rule 506 of Regulation D and otherwise meet the finanacial investment standards so required by each joint venture manager.

Passive Income:
 Income that does not require active participation.

Per Annum:
 The amount of return on investment each year.

Power of Attorney:
 A written instrument duly signed and executed by an individual which authorizes an agent to act on his behalf to the extent indicated in the document.

Private Placement Offerings (PPO):
 The sale of securities directly to institutional investors, such as banks, mutual funds, insurance companies, pension funds, and foundations. Does not require SEC registration, provided the securities are bought for investment purposes rather than resale, as specified in the investment letter.

Profit:
 The positive gain from an investment or business operation after subtracting for all expenses. Opposite of loss.

Rate of Return:
 The annual rate of return on an investment, expressed as a percentage of the total amount invested. Also called return.

Return on Investment (ROI):
 The income that an investment provides in a year.

SEC:
 The Securities and Exchange Commission.

Subscription Agreement:
 An application by an investor to join a limited partnership. In most cases, the investor will have to fill out a form created by the general partner evaluating the investor's suitability for the investment in the partnership. Note:
All limited partners must be approved by the general partner. Becoming a limited partner rather than a partner is an attractive option since it means the investor's liability is limited to the amount he or she has invested in the partnership.

Terms:
 The period of time that an agreement is in effect.