Choke manifold

A choke manifold, which consists of a series of remotely controlled valves, allows the driller to control and relieve downhole pressures, following a kick . 

The manifold is typically a tubular steel structure (similar to a template) which is host to a series of remotely operated valves and chokes. It is common for subsea tree control systems to be mounted on the manifold and not on the individual trees. A complex manifold will generally have its own set of dedicated subsea control modules (for controlling manifold valves and monitoring flowline sensors). 

Control can be exercised by the operator in the control roam on the well chokes and manifold divert valves (although this is normally handled by the HOC), start/atop of the oil shipping pumps, utility equipment, switching valves, gas plant feed valves, gas compressor start/stop and emergency shutdown of any production train or the entire GC. Since the closed loop process control is performed by local pneumatic instruments, all set point changes and controller troubleshooting must be accomplished locally. 

An important feature of the distributed control system chosen is that the PCMs can communicate over a microwave link, thus allowing the well pad manifold modules to be included in the GC control system the hardwire data highway is limited to a distance of 5000 ft. (1524m) from the Host. The well chokes and manifold controls will remain on the SCAOA system, but the well pad will require continuous process control of the test separator, water injection flow control, and artificial lift gas flow control. 

It is possible to theoretically trace particle size distribution up the tubing, through the choke, flowlines, manifolds and production equipment into the free water knockout using equations presented in previous installments However, many parameters needed to solve these equations, especially those involving coalescence, are unknown... 

Application of the center manifold theorem [1] to system (1) leads to a statement of very great generality. With its aid it is possible to characterize the topology of the ensemble of all solutions of system (1). This is done in a phase space ft of n+1 dimensions consisting of the union a U z. The key to the understanding of choking is in the identification of the singular points of system (1) whose coordinates in phase space ft are solutions o, z of the simultaneous equations... 

Consideration should be given to the layout of the major components of the drilling rig s well control equipment, to include the layout and location of the choke/kill manifold, choke control panel, mud/gas separator, gas discharge line, trip tank, BOP, and control panels so that adequate space is provided and operational safety not compromised. 

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