J

J Slot
A locking arrangement utilizing a slot in the form of a j and a pin which prevents premature setting of bottomhole equipment and at the same time provides a method of surface control for setting the equipment at the proper time and depth.

Jack Board
A device used to support the end of a length of pipe while another length is being screwed on.

Jack Line
The pull rod line running from a central power unit to a pumping jack.

Jack Screw
A screw or bolt used to spread two elements apart.

Jack Shaft
A short shaft between the couplings on a rotating unit and its drive.

Jacker (platform)
A supporting structure for an offshore platform.

Jacker (well)
A protective structure surrounding a wellhead in shallow water, usually fabricated of either steel or wood.

Jacket
(1) The lower or supporting section of a platform.(2) A tubular piece of steel in a tubing liner type of sucker rod pump, inside of which is placed an accurately bored and honed liner. In this type of sucker rod pump, the pump plunger moves up and down within the liner, and the liner is inside the jacket.

Jacketed Cable
Cable with a nonmetallic protective covering.

Jar
A percussion tool that operates on a mechanical or hydraulic principle and is designed to deliver a heavy hammer blow to objects in the borehole to which it is attached. Jars are used for such purposes as freeing objects stuck in the borehole in fishing operations or imparting a jarring motion to stuck tools for the purpose of freeing them. The design of the jar often permits blows to be delivered in either a downward or upward direction, with control being regulated at the surface. To apply a heavy upw

Jar Accelerator
A hydraulic tool used in conjunction with a jar. The accelerator is made up in the fishing string above the jar and serves to increase the magnitude of the jarring blow delivered to the fish.

Jar Test
Pretesting in small containers to see what the reaction will be before large volumes are utilized. Generally used to show the effects of adding chemicals to fluids to produce a change; i.e., if the chemical will break an emulsion.

Jet Bit
SEE: Jet Type Bit.

Jet Bit Deflection
A method of changing the inclination angle and direction of the borehole axis by using the washing action of a jet nozzle at one side of the drill bit.

Jet Nozzle
A fluid flow port in a jet bit.

Jet Perforating
An operation similar to gun perforating except that a shaped charge of high explosives is used to burn a hole through the casing instead of using the gun which fires a projectile.

Jet Spud Bit
A special bit used to cause deflection of the borehole axis by a combination of jetting and spudding action.

Jet Type Bit
A bit employing directed, rapid flow of fluid from a nozzle or nozzles.

Jetting
(1) The action of causing erosion of the borehole wall by the high pressure impact of drilling fluid.(2) The process of periodically removing a portion of, or all, water, drilling fluid, and/or solids from the pits, usually by means of pumping through a jet nozzle arrangement.

Jetting Runs
Trips, jetting and drilling made to change the inclination and direction of the borehole axis.

Jib
An extension attached to the boom to provide added boom length for lifting specified loads. Also referred to as Tip Extension.

Joint
The place or part where two lengths of tubular goods or sucker rods are joined or united. Oil field vernacular usually refers to one length of tubular goods (usually 20-30 feet long) as one joint.

Joint Account
The account showing the charges paid and credits received as a result of the Joint Operations and which are to be shared by the parties in accordance with the terms of the agreement.

Joint Audit Data Exchange
An Electronic Data Interchange (EDI) group that provides outside auditors with voucher listings on personal computer diskettes for upstream joint interest properties. Also referred to as JADE.

Joint (blast)
An external coated tube set across the producing interval to protect against the effects of abrasing sands or abnormal pressures.

Joint Interest Billing Exchange
An Electronic Data Interchange (EDI) group that is the electronic transmission of invoices and operating statements on upstream properties. This is the first petroleum exchange using American National Standards Institute (ANSI) formats. Also referred to as JIBE.

Joint Operation
An operation necessary or proper for the exploration, development, operation, protection, and maintenance of a joint property.

Joint Property
The real and personal property and/or area of interest subject to the agreement in effect.

Joint (rock)
A linear break within a rock strata without movement of one side of the joint relative to the other.

Joint Venture
A sharing of the total working interest in a property by two or more parties.

Joint Volume Estimate
The volume per stand or joint which should be gained or lost from the trip tank due to the movement of the pipe.

Jointer
A length of pipe made up of two shorter pieces of pipe.

Jointly Owned Lease
A lease owned jointly by two or more working interest owners.

Jones Effect
The net surface tension of salt solutions first decreases with an increase of concentration, passes through a minimum, and then increases as the concentration is raised.

Julian Date
A system of dating which counts the number of days from a given base date, normally the beginning of a calendar year; e.g., January 1, 1991 is represented by 91001; December 31, 1981 is represented by 81365.

Junk
The metal debris lost in a wellbore. Junk may be lost tools, pieces of wire, or any relatively small object that impedes activity to the extent that it must be fished out of the wellbore.

Junk Basket
A fishing tool run into the wellbore when it is necessary to retrieve small parts or lost tools.