Chapter 1 Flashcards
Hydrocarbon accumulations in geological traps can be classified as…
Reservoir
Role of this engineer is to maximize oil and gas production in a cost-effective manner
Production Engineer
Reservoir, Well, Flow-line, Separators, Pumps, and Transportation pipelines
Complete Oil/Gas Production System
Supplies wellbore with crude oil or gas
Reservoir
Provides a path for the production fluid to flow from bottom hole to surface and offers a means to control the fluid production rate
Well
Leads the produced fluid to separators
Flowline
Remove gas and water from the crude oil
Separators
Used to transport oil and gas through pipelines to sale points
Pumps and Compressors
An area that consists of one or more reservoirs all related to the same structural feature
Field
Contains one or more reservoirs in isolated structures
Pool
An oil is at a pressure above its bubble-point pressure. It can dissolve more gas at the given temperature.
Undersaturated Oil
An oil that is at its bubble point pressure. It can dissolve no more gas at the given temperature.
Saturated Oil
prevails in an undersaturated oil reservoir.
Single (liquid) Phase flow
Exists in a saturated oil reservoir
Two-phase (liquid oil and free gas)
GOR
Gas-Oil-Ratio
____ Wells producing GOR greater than 100,000 SCF/STB
Gas Wells
____ Wells that are producing GOR less than 100,000 SCF/STB but greater than 5,000 SCF/STB
Condensate Wells
___ Reservoirs can be classified on the basis of boundary type
- Water- Drive Reservoir
- Gas- Cap Reservoir
- Dissolved- gas drive reservoir
Oil
In ___ reservoirs, the oil zone is connected by a continuous path to the surface groundwater system.
Water-Drive Reservoir
Surface Groundwater System
Aquifer
The most preferable type of reservoir compared to bottom-water drive because the reservoir pressure can remain at its initial value above bubble-point pressure so that single-phase liquid flow exists in the reservoir for maximum well-productivity.
Edge-Water Drive Reservoir
___ flow condition can prevail in an edge-water drive reservoir for a long time before water breakthrough into the well.
Steady-State Flow
____ Reservoir is less favorable because of water-coning problems that can affect oil production economics due to water treatment and disposal issues.
Botton-Water Drive Reservoir
___ Reservoir, the drive mechanism where the gas in the reservoir has come out of the solution and rises to the top of the reservoir to form a gas cap. The oil below the gas cap can be produced. If the __ is taken out of the reservoir early in the production process, the reservoir pressure will decrease rapidly.
Gas-Cap Drive Reservoir
A type of reservoir that has a fixed oil volume surrounded by no-flow boundaries (faults or pinch-outs). It is the drive mechanism where the reservoir gas is held in solution in the oil (and water). The reservoir gas is actually in a liquid form in a dissolved solution with the liquids at atmospheric conditions from the reservoir. Compared to the Water and gas drive reservoirs, expansion of solution (dissolved gas) in the oil provides a weak driving mechanism in a volumetric reservoir.
Dissolved-Gas Drive Reservoir/ Solution-gas Drive Reservoir/ Volumetric Reservoir
In Volumetric Reservoir, the regions where the oil pressure drops to below the bubble-point pressure, gas escapes from the oil and oil-gas two-phase flow exists. In order to improve oil recovery in the solution-gas reservoir…
Early pressure maintenance is usually preferred.
Most wells produce oil through ___, because it provides good sealing performance and allows the use of gas expansion to lift oil.
Tubing Strings
Steel Grades of tubing are designated H-40, J-55, C-75, L-80, N-80, C-90, P-105. The digits represent…
Tubing.
Digits represent the minimum yield strength in 1,000 psi.
___ is defined as the surface equipment set below the master valve.
Well-head
___ is threaded onto the surface casing
Lowermost casing head
mechanical assembly used for hanging a casing string. Has a bowl that supports the casing hanger.
Casing Head
___ is threaded onto the top of the production casing or uses friction grips to hold the casing.
Casing Hanger
As in the case of production tubing, the ___ is landed in tension so that the casing hanger actually supports the production casing down to the freeze point.
Production Casing
Most flowing wells are produced through a string of tubing run inside the ___.
Production Casing String
At the surface, the tubing is supported by the ____, is used for hanging tubing string on the production casing head. It supports the tubing string at the surface (this tubing is landed on the tubing head so that it is in tension all the way down to the packer).
Tubing Head
Equipment at the top of the producing wellhead is called…used to control flow. It is installed above the tubing head. __ may have one flow outlet or two flow outlets.
Christmas Tree
A(n) ___ is used to join the Christmas Tree and the Tubing Head.
Adaptor
One flow outlet on a Christmas Tree.
Tee
Two flow outlet on a Christmas Tree
Cross
This is installed below a Tee or a Cross
Master Valve
___ consists of a main valve, wing valves, and a needle valve. Used for closing the well when needed.
Christmas Tree.
On top of a Christmas Tree, there is a ___ that indicates the ___ in the tubing.
Pressure gauge, Pressure in the tubing
Piece of equipment used to control the flow rate
Surface Choke
In most flowing wells, the oil production rate is altered by adjusting the…which causes back-pressure in the line.
Choke Size
This causes back-pressure
Chokes
____ increases the bottom hole flowing pressure.
Back-Pressure
Increasing the bottom-hole flowing pressure decreases the pressure drop from the reservoir to the ___.
Wellbore (Pressure drawdown)
When chokes are installed in the lower section of tubing strings… it ___ well head pressure and ___ oil production rate as a result of gas expansion in the tubing string.
Decreases well head pressure and enhances oil production rate
What is the major disadvantage of installing a down-hole choke?
Too expensive
What must be done before opening the well?
Check all the surface equipment such as safety valves, fittings, etc.
T/F The burner of a line heater must be lit before the well is opened. This is necessary because the pressure drop across a choke cools the fluid and may cause gas hydrates or paraffin to deposit out.
True
T/F The upsteam heating helps melt any solids that may be present in the producing fluid. The downstream heating prevents hydrates and paraffins from forming at the choke
True
T/F It is not necessary for surface vessels to be open and clear before the well is allowed to flow
False
T/F To open the well, be sure that all valves that are in the master valve and downstream valves are closed.
True
T/F The procedure for “Shutting-in” a well is the same as the procedure for opening a well.
False, it is opposite.
T/F In shutting-in the well, the master valve is closed last.
True
T/F Valves are closed quickly.
True, Valves need to avoid wearing/ erosion. At least two valves must be closed.
T/F There are two types of separators.
False, There are three types of separators; horizontal, vertical, spherical.
___ are categorized into two categories. Single and double tube.
Horizontal Separator
__ separators are usually the first choice because of their low costs.
Horizontal Separator
__ separators are almost widely used for high-GOR well streams, foaming well streams, or liquid-from-liquid separation since they have much greater gas-liquid interface because of a large, long, baffled gas-separation section. They are easier to skid-mount and service and require less piping for field connections.
Horizontal Separator
Individual separators can be stacked easily into stage separation assemblies to minimize space requirements. Gas flows ___, while liquid droplets fall towards the liquid surface.
Horizontal Separator
__ separators are often used to treat low to intermediate GOR well streams and streams with relatively large slugs of liquid. They handle greater slugs of liquid without carryover to the gas outlet, and the action of the liquid-level control is not as critical. They occupy less floor space, which is important for facility sites like offshore platforms.
Vertical Separators
___ separators offer an inexpensive and compact means of separation arrangement. These types of separators have very limited surge space and liquid-settling section. The placement and action of the liquid-level control in this type of separator is more critical.
Spherical Separators
____ are used to provide mechanical energy required for the transportation.
Reciprocating piston pumps
___ is used for duplex (two piston pumps)
Double-Action Stroke
___ is used for umps with three pistons or greater (triplex pump).
Single-action stroke
___ are used for providing gas pressure required to transport gas with pipelines and to lift oil in gas-lift operations.
Compressors
Two Types of of Gas Compressors
Reciprocating and Rotary Compressors
___ are most commonly used in the natural gas industry built for practically all pressure and volumetric capabilities. They have more moving parts and lower mechanical efficiencies. Each cylinder assembly of a ___ compressor consists of a pison, cylinder, cylinder head, suction and discharge valves, and other parts necessary to convert rotary motion to reciprocation motion.
Reciprocating Compressors
____ compressors are divided into two classes: the centrifugal compressor and rotary blower.
Rotary Compressor
____ compressor consists of a housing with flow passages, a rotating shaft on which the impeller is mounted, bearings, and seals to prevent gas from escaping along the shaft.
Centrifugal Compressor
___ compressor have few moving parts because only the impeller and shaft rotate thus its efficiency is high and lubrication oil consumption and maintenance costs are low. Cooling water is normally unnecessary because of lower compression ratio and less friction loss.
Centrifugal Compressor
Compression rates of centrifugal compressors are ___ because of the absence of positive displacement.
Lower
T/F Centrifugal compressors compress gas using centrifugal force.
True, Work is done on the gas by an impeller. Gas is then discharged at a high velocity into a diffuser where the velocity is reduced and its kinetic energy is converted to static pressure.
