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Hydraulics
Bit Technology
Directional Drilling
Well Control
Kicks, Kick Control, Kick Control Methods
Well Control Equipment, Pressure Control Theory, 'Special Kicks Problems & Procedure
Deflection Tools & Techniques
Whipstocks, Jetting, Downhole motor and bent sub, Control with Rotary Assemblies
Manifolds/gathering
Onshore, the individual well streams are brought into the main production facilities over a network of gathering pipelines and manifold systems. The purpose of these is to allow set up of production “well sets” so that for a given production level, the best reservoir utilization, well flow composition (gas, oil, waster) etc. can be selected from the available wells.
For gas gathering systems, it is common to meter the individual gathering lines into the manifold as shown on the illustration. For multiphase (combination of gas, oil and water) flows, the high cost of multiphase flow meters often lead to the use of software flow rate estimators that use well test data to calculate the actual flow.

Offshore, the dry completion wells on the main field centre feed directly into production manifolds, while outlying wellhead towers and subsea installations feed via multiphase pipelines back to the production risers. Risers are the system that allow a pipeline to “rise” up to the topside structure. For floating or structures, this involves a way to take up weight and movement. For heavy crude and in arctic areas, diluents and heating may be needed to reduce viscosity and allow flow.
Pipelines, and Risers
This facility uses Subsea production wells. The typical High Pressure (HP) wellhead at the bottom right, with its Christmas tree and choke, is located on the sea bottom. A production riser (offshore) or gathering line (onshore) brings the well flow into the manifolds. As the reservoir is produced, wells may fall in pressure and become Low Pressure (LP) wells.
This line may include several check valves. The choke, master and wing valves are relatively slow, therefore in case of production shutdown, pressure before the first closed sectioning valve will rise to the maximum wellhead pressure before these valves can close. The pipelines and risers are designed with this in mind.
Short pipeline distances is not a problem, but longer distances may cause multiphase well flow to separate and form severe slugs, plugs of liquid with gas in between, traveling in the pipeline. Severe slugging may upset the separation process, and also cause overpressure safety shutdowns. Slugging might also occur in the well as described earlier. Slugging may be controlled manually by adjusting the choke, or with automatic slug controls. Further, areas of heavy condensate might form in the pipelines. At high pressure, these plugs may freeze at normal sea temperature, e.g. if production is shut down or with long offsets. This may be prevented by injecting ethylene glycol. Glocol injection is not used on Njord.
The Njord floater has topside chokes for Subsea wells. The diagram also shows that Kill Fluid, essentially high specific gravity Mud, can be injected into the well before the choke.
Manifold & gathering of Oil and gas


Oil and Gas Production
Production Technology Foundation
Oil & Gas Production System
Oil & Gas Production Introduction
Gas Properties
Formation Damage
Radial Flow and Formation Damage
Causes and Effects of Sand Production
Predicting Sand Production
Sand Control Techniques
Gravel Pack Sand Design
Slotted Liner and Wire Wrapped Liners
Gravel Pack Completion Equipment and Service Tools
Well Preparation for Gravel Packing
Cleaning the Casing Open Hole Work String ; Surface Facilities
Open Hole Gravel Packing
Oil and Gas Pipeline
Design of Marine Pipeline
Petroleum Videos
Production Technology Foundation
Oil & Gas Production System
Oil & Gas Production Introduction
Design and Installation of Marine
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