Flow module placement between a subsea tree and a tubing hanger spool

Abstract

A subsea wellhead assembly positions a flow module between an outboard flowline of a subsea tree and a tubing hanger spool flowline. The subsea production assembly includes a wellhead, a tubing hanger spool disposed on the wellhead, and a subsea tree disposed on the tubing hanger spool. Production fluid may flow from the wellhead through the tubing hanger spool, and then through the tree. A tubing hanger spool frame mounts to and extends laterally from the tubing hanger spool and supports a downstream flowline having an upward facing hub. A tree frame mounts to and extends laterally from the subsea tree and supports an upstream flowline having an upward facing hub. A flow module having downward facing flowlines that couple to the hubs so that the weight of the flow module is distributed between the frames of the tubing hanger spool and the subsea tree.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates in general to subsea production apparatuses and, in particular, to an improved flow module placement between a subsea tree and a tubing hanger spool.[0003]2. Brief Description of Related Art[0004]A conventional subsea wellhead assembly includes a wellhead housing that supports one or more casing hangers located at upper ends of strings of casing extending into the well. A tubing hanger spool or “THS” is landed on the wellhead assembly. A production tree or “tree” is landed on the THS for controlling the production of well fluids. The tree usually carries a choke and valves to control the flow of well fluids and sensors to monitor the flow of well fluids.[0005]The subsea tree will control the flow of hydrocarbons out of the wellhead, and direct the hydrocarbons to associated equipment, such as manifolds, flowlines, and the like for further operation. Subsea trees may have a flow module, such as a c...

AI Technical Summary

Benefits of technology

[0012]An advantage of a preferred embodiment is a shorter flow path from the flow module to external production devices. This leads to a reduction in the pressure drop across the system, and a reduction in the amount of heat lost through the outboard flowlines. In addition, the shorter flowline provides fewer opportunities for leaks to occur. Still further, the disclosed embodiments allow for production of the subsea production assembly at a reduced cost. This arises as a result of the significant decrease in the amount of material needed to connect the flow module to the external production devices, and a decrease in the man-hours needed to construct the tree and flow module.

Problems solved by technology

Portions of the tree, such as flow meters, or chokes that control the flow of hydrocarbons through the outboard flowlines, may wear and fatigue at rates faster than the remaining portions of the subsea tree.

As a result, there is a significant pressure drop through the outboard flowline from the flow module.

In addition, the longer outboard flowline from the flow module leads to a greater heat loss from the well fluid into the surrounding environment.

This can lead to an increase in the viscosity of the well fluid.

Furthermore, the length of the outboard flowline from the flow module increases the total area from which leaks can form; thus the longer outboard flowline from the flow module increases the likelihood of leak development.

The length of the outboard flowline from the flow module may also cause an increase in the cost of production.

This results from both the increase in the amount of material needed to construct the line and the increased labor cost to construct the lengthy outboard flowline from the flow module.

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