Target Energy - Australian petroleum exploration and production company.

MAKING HOLE
Refers to progress being made at a given time when the bit is rotating and the well-bore is being deepened. In other words, drilling.

MAKING A TRIP
Hoisting of the drill string out of, and returning it into, the well bore. This is done for the purpose of changing bits, preparing to take a core, etc.

MAKE UP/BREAK OUT
To assemble/screw together the sections of joints of a string of pipe. 'Breaking out' is the opposite.

MARGINAL
A well, development, etc. whose commercial profitability is in doubt.

MIGRATION
Hydrocarbons are often found in formations other than those in which their organic source was deposited. This movement often over considerable distances is known as migration. A process applied to data recorded, e.g. in a "3-D" seismic survey, to adjust for the effects of the "oblique" angle at which it was gathered.
 
MILLIDARCY
See Darcy

MINIMUM ROYALTY
The lowest payment a lessee can pay on an OCS lease after production begins. It is equivalent to the yearly rental, typically $3 per acre or $8 per hectare. Rentals are paid annually before a discovery; royalties are paid on production after a discovery. If the total royalty payments amount to less than the yearly rental, the minimum royalty payments make up the difference.

MMBBL
Million barrels.

MMBOE
Millions of barrels of oil equivalent.

MMSCFD
Millions of standard cubic feet per day.

MUD
Mud is the name given to drilling fluid which is mainly a mixture of water, or oil distillate, and 'heavy' minerals such as Bentonite or Barites. Mud is pumped into a well at densities calculated to provide a hydrostatic pressure sufficient to overcome downhole formation pressures. (See e.g. Gas Kick). In addition, the mud is continuously circulated down to the bit, and returns in the annular space outside the drill-string, bringing with it rock cuttings for inspection and keeping the well clean. It is also engineered to maintain a thin protective layer of filter-cake on the bore hole wall, without excessive weight which would decrease the weight on the bit and hence penetration ( see Drill String), and also possibly lead to differential sticking and formation damage. Mud is pumped from the mud pit (or tank) via the standpipe, rotary hose and gooseneck to the swivel, and into the drill stem. On return from down hole it is recovered and rock cuttings removed by the shale shakers before re-circulation. A Mud Log is the record of mud make-up and analysis of cuttings recovered.

MULTIPLE ZONE WELL COMPLETION
Completion of a well in such a way that production is obtained from several different formations.


NET PROFIT SHARE LEASE
An OCS lease that provides for payment to the U.S. of a percentage share of the net profits for production of oil and gas from the tract. The percentage share may be fixed in the notice of the lease sale or may be a variable of the bid, depending on the bidding system used for the lease sale.

NODDING DONKEY
The colloquial name for conventional onshore wellhead production beam pumps.


OFFSET WELL
Well location adjoining another well site.
 
OIL IN PLACE (OIP)
See In Place

OIL COLUMN/GAS COLUMN
The vertical distance between points of highest and lowest known oil or gas in a reservoir.
 
OIL/WATER CONTACT
The lower end of the oil column in a reservoir with underlying water. This may be graduated or occur in formations where it is hard to detect.

ON STREAM
When production is flowing, or plant is in operation.

OPEN FLOW
Producing a well without chokes or beans. Unrestricted production normally for testing or maintenance purposes.

OPEN HOLE
An uncased section of well borehole.

OPERATOR
Person, whether proprietor or lessee, who actually operates the well. Generally, the oil company by whom the drilling contractor is engaged.


P10
The value for which there is at least a 10% probability that
the quantities actually recovered will equal or exceed that
value.

P50
The value for which there is at least a 50% probability that
the quantities actually recovered will equal or exceed that
value.

P90
The value for which there is at least a 90% probability that
the quantities actually recovered will equal or exceed that value.

PACKER
A seal used to isolate a section of a well, eg for testing or production from one of several formations. Packers are also used in operations such a cementing and acidising.

PAY, PAY SAND, OR PAY SECTION 
Producing formation, or that formation which represents the objective of drilling.
  
PAY ZONE/HORIZON
A formation containing producible hydrocarbons.

PERFORATE
To pierce holes through well casing within an oil or gas-bearing formation by means of a perforating gun lowered down the hole and fired electrically from the surface. The perforations permit production from a formation which has been cased off.

PERFORATION/PERFORATING GUN
Holes punched in the casing of a well at the pay zone to be produced, to allow oil or gas to enter the well.  A Perforating Gun is a cylindrical tool loaded with explosive charges which are triggered opposite the pay zone, perforating the casing in many places.

PERMEABILITY
The degree to which a body of rock will permit a fluid to flow through it. It is a function of the shape of the capillary pore spaces and the degree to which pores are connected.

PETROLOGY
The study of rocks, their origin, chemical and physical properties and distribution.

PINCH OUT
The thinning out and disappearance over a distance of a formation, eg an oil bearing sandstone between layers of impermeable rock.

PIPE    
Oilfield tubular goods such as casing, drill pipe, tubing, or pipeline.

PIPE RACK
Where stands of drill pipe are stacked vertically in a derrick ready for use. Racks or frames are also sometimes used to store tubulars horizontally in yards and or offshore decks, and when transporting them offshore.

PIPE RAMS
Hydraulic rams in a blowout preventer which are shaped to fit around the drill-stem and seal the annulus. Blind Rams are designed in extreme emergency to shear through the drill pipe and seal the well completely.

PLUG/PLUG AND ABANDON
To seal a well, or part of a well with cement, e.g. before producing from a higher formation, sidetracking, or leaving the well permanently sealed and abandoned.

POOL
An Oil Pool is a reservoir or group of reservoirs sharing a common pressure system.

POROSITY
The volume of free space between the grains of a rock capable of holding fluid, (gas or liquid). It is expressed as a percentage of total gross rock volume.

PRESSURE BOMB
A down hole pressure recording capsule used in well monitoring.

PROBABLE RESERVES
Those unproved reserves which analysis of geological and engineering data suggests are more likely than not to be recoverable. In this context, when probabilistic methods are
used, there should be at least a 50% probability that the quantities actually recovered will equal or exceed the sum of estimated Proved plus Probable Reserves. When probabilistic methods are used this corresponds to P50 value.

PRODUCIBLE LEASE
A lease where one well or several wells have discovered hydrocarbons in paying quantities, but for which there is no production during the reporting period.

PRODUCIBLE ZONE COMPLETION
The interval in a wellbore that has been mechanically prepared to produce oil, gas, or sulphur. There can be more than one zone completed for production in a wellbore.

PRODUCING LEASE
A lease that is producing oil, gas, or sulphur in quantities sufficient to generate royalties.

PRODUCTION
The operation of bringing the well fluids to the surface and separating them, and storing, gauging, and otherwise preparing product for the pipeline. Also refers to the amount of oil or gas produced over a given period

PRODUCTION CASING STRING
The innermost steel lining of a well cemented in place and perforated for production in the pay zone. Note that production tubing is inserted inside this casing.

PRODUCTION TESTING
A production test concerns the capability to produce (productivity) of a well and its effects on the reservoir produced. A production test may continue for several months where extensive data is necessary prior to final commitment to development expenditures etc.

PRODUCTION TUBING STRING
The string of pipe installed inside the casing of a production well, to a point just above the reservoir through which the fluids are produced. It may be 2" to 5" diameter or more, depending on the production flow and pressures anticipated.

PRODUCTION WELL/PRODUCER
A development well specifically for the extraction of reservoir fluids.

PRODUCTION WELLHEAD AND TREE
The assembly of casing head, tubing head, connections and well-control valves fitted to a producing well. The "Christmas Tree" is the name given the complete assembly of valves, connecting flanges etc.

PRODUCTIVITY/PRODUCTIVITY INDEX
The continuous productive capacity of a well. The Index is measured as volume produced (e.g. barrels per day) divided by the drop in pressure (p.s.i.) to achieve that flow rate starting with a "shut in" pressure.

PROSPECTIVE RESOURCES
Those quantities of petroleum which are estimated on a given date, to be potentially recoverable from undiscovered accumulations.

PROVED RESERVES
Those quantities of oil and gas which, by analysis of geological and engineering data, can be estimated with reasonable certainty to be commercially recoverable, from a given date forward, from known reservoirs and under current economic conditions, operating methods and government regulations. When probabilistic methods are used this corresponds to the P90 value.

PULLING OUT
Retrieving and stacking the drill-string on reaching target depth.

PUP JOINT
A joint of pipe of non-standard length, to make up a string of tubulars to an exact required total length.