Patent Application
20210230976
This disclosure relates generally to subsea oil and gas production facilities, and particularly to interconnecting conduits extending between subsea components. The disclosure further relates to thermal management of such interconnecting conduits.
The production of hydrocarbons from offshore oil and gas reservoirs requires the transportation of production fluids from the reservoirs to subsea facilities for processing. Three phases, i.e., oil, gas and water, may be included in the production fluids. Subsea developments increasingly must accommodate high temperature production fluids that need to be safely transported to the production facility. The high temperature of the production fluids can have several undesirable effects. Special grade subsea and pipeline materials, extensive qualifications of insulation coating and expensive modifications topsides may be required to handle the high temperature of the product. For instance, water cooled heat exchangers may be used topsides on an offshore platform to reduce the temperature of production fluids, e.g., from around 400° F. to a temperature below 250° F., involving weight, space, cost, etc. In the subsea facility, the high temperature of the product may undesirably result in the occurrence of upheaval buckling, lateral buckling and pipeline walking in flowlines carrying the product. The temperature may also undesirably accelerate corrosion and therefore reduce the life of the flowlines. Attempts have been made at providing a subsea cooling system for use with gas production. No established oil or three phase subsea cooling system is available in the industry.
There exists a need for cost-effective subsea cooling systems and methods that can be applied to subsea flowlines or interconnecting conduits such as jumpers that carry three-phase production fluids to enable the development of high temperature subsea fields without the disadvantages of known systems.
In general, in one aspect, the disclosure relates to a system for thermal management of a subsea conduit that carries oil and/or gas produced from a subsea well in a subsea production facility located on a seabed. The system includes an interconnecting conduit for carrying production fluids having a length, an outer diameter and two ends for connecting to subsea components. An annular pipe section having two ends, an annular pipe section length, and an annular pipe section outer diameter greater than the interconnecting conduit outer diameter surrounds at least a portion of the interconnecting conduit. A fluid inlet at one of the two ends of the annular pipe section can receive liquid cooling medium into the annular pipe section when the fluid inlet is opened. A fluid outlet at the other of the two ends of the annular pipe section can discharge liquid from the annular pipe section when the fluid outlet is opened. A control system can be set to open or close the fluid inlet and open or close the fluid outlet based on a predetermined fluid temperature and/or flow rate.
In another aspect, the disclosure can generally relate to a method for thermal management of the subsea conduit in the subsea production facility. The method includes transmitting fluids comprising oil and/or gas produced from the subsea well through the interconnecting conduit having the annular pipe section as described above surrounding at least a portion of the interconnecting conduit concentrically. The control system opens and closes the fluid inlet and the fluid outlet when a detected fluid temperature and/or flow rate of the transmitted fluids reach a predetermined fluid temperature and/or flow rate, thereby adjusting an amount of heat transfer between the interconnecting conduit and the annular pipe section.
These and other objects, features and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings. The drawings are not considered limiting of the scope of the appended claims. Reference numerals designate like or corresponding, but not necessarily identical, elements. The drawings illustrate only example embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey such principles.
Referring to
Systems and methods are described herein for thermal management of subsea conduit for carrying oil and/or gas produced from a subsea well in a subsea production facility in ways not possible using prior art methods. The system includes an interconnecting conduit circuit 2, also referred to herein as a jumper circuit 2, for carrying production fluids between subsea components (e.g., manifolds, wellheads, pipeline end terminations, and other equipment residing on the seabed). The conduit or jumper can be any suitable device as known for permitting the flow of produced fluids therethrough, e.g., a spool, a jumper or a pipe. The jumper has two ends for connecting to subsea components, such as but not limited to wellheads, manifolds, pipeline end terminations (PLETs), and the like. In various embodiments, the jumper is self-draining and can have variable insulation to manage operation when cooling is needed as well as shutdown or late stage when heat retention is needed. The system advantageously provides the ability to adjust between cooling mode during normal operation and heat retention mode during shut down or late life operation.
In one embodiment, referring to
In one embodiment, referring to
In all embodiments, insulation 3 can optionally surround the annular pipe section 4.
Returning to
In one embodiment, a temperature sensor 8 and/or a flow rate sensor 9 are used to detect a fluid temperature and/or flow rate of the fluids transmitted in the jumper 2. In one embodiment, the system further utilizes a control system 6 having a processor 7 configured to receive temperature and/or flow rate information on fluid flowing through the jumper 2 from the temperature sensor 8 and/or the flow rate sensor 9, respectively. The fluid temperature and/or flow rate data is transmitted from the temperature sensor and/or the flow rate sensor to the control system by a flying lead or an umbilical 12. The control system 6 can be configured to open and close the fluid inlet 4A and the fluid outlet 4B when the detected fluid temperature and/or flow rate reach a predetermined fluid temperature and/or flow rate. The control system 6 can thereby adjust an amount of heat transfer between the jumper 2 and the annular pipe section 4 having the liquid cooling medium therein.
The processor 7 can be configured to determine whether to activate an alarm indicating the need to open or close the fluid inlet 4A and the fluid outlet 4B based on the predetermined fluid temperature and/or flow rate as detected in the jumper 2 by the temperature sensor 8 and/or a flow rate sensor 9, respectively.
In one embodiment, referring to
In one embodiment, referring to
In one embodiment, referring to
In one embodiment, the fluid inlet 4A and the fluid outlet 4B are opened and closed by an ROV (not shown). In one embodiment, the control system 6 is configured to open and close the fluid inlet 4A and the fluid outlet 4B automatically as needed as determined by the processor 7.
It should be noted that only the components relevant to the disclosure are shown in the figures, and that many other components normally part of a subsea oil and gas field are not shown for simplicity.
For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present invention. It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural references unless expressly and unequivocally limited to one referent.
Unless otherwise specified, the recitation of a genus of elements, materials or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof. Also, “comprise,” “include” and its variants, are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the materials, compositions, methods and systems of this invention.
