Flow control nozzle and system

#The present description relates to flow control devices used for controlling flow of fluids into a tubular member. In a particular example, the described flow control devices control, or choke, the flow of steam from subterranean formations into production tubing.

#Subterranean hydrocarbon reservoirs are generally accessed by one or more wells that are drilled into the reservoir to access the hydrocarbon materials. Such materials are then brought to the surface through production tubing.

#The wellbores drilled into the reservoirs may be vertical or horizontal or at any angle there-between. In some cases, the desired hydrocarbons comprise a highly viscous material, such as heavy oil, bitumen and the like. In such cases, it is known to employ steam, gas or other fluids, typically of a lower density to assist in the production of the desired hydrocarbon materials. These agents are typically injected into one or more sections of the reservoir to stimulate the flow of hydrocarbons into production tubing provided in the wellbore. Steam Assisted Gravity Drainage, “SAGD”, is one example of a process where steam is used to stimulate the flow of highly viscous hydrocarbon materials (such as heavy oil, bitumen etc. contained in oil sands). In a SAGD operation, one or more well pairs, where each pair typically comprises two vertically separated horizontal wells, are drilled into a reservoir. Each of the well pairs typically comprises a steam injection well and a production well, with the steam injection well being positioned generally vertically above the production well. In operation, steam is injected into the injection well to heat and reduce the viscosity of the hydrocarbon materials in its vicinity, in particular viscous, heavy oil material. After steam treatment, the hydrocarbon material, now mobilized, drains into the lower production well owing to the effect of gravity, and is subsequently brought to the surface through the production tubing.

#The features of certain embodiments will become more apparent in the following detailed description in which reference is made to the appended figures wherein:

#FIG. 1 is a side cross-sectional view of an inflow control nozzle according to an aspect of the present description.

#FIG. 1a is an end view of the inlet of the nozzle of FIG. 1.

#As used herein, the terms “nozzle” or “flow control device”, as used herein, will be understood to mean a device that controls the flow of a fluid flowing there-through. In one example, the nozzle described herein is an “inflow control device” or “inflow control nozzle” that serves to control the flow of fluids through a port from a subterranean formation into a pipe for production operations. It will be understood, that such nozzles may also allow for flow of fluids in an opposite direction, such as for injection operations.

#The terms “regulate”, “limit”, “throttle”, and “choke” may be used herein. It will be understood that these terms are intended to describe an adjustment of the flow rate of a fluid passing through the nozzles described herein. As discussed herein, the present nozzles are specifically designed to choke the flow of a low viscosity fluid, in particular steam. For the purposes of the present description, the flow of a fluid is considered to be “choked” if a further decrease in downstream pressure does not result in an increase in the velocity of the fluid flowing through the restriction. That is, the fluid velocity is limited and as a result, and assuming that all other variables remain unchanged, the mass flow rate of the fluid is also limited.

#The term “hydrocarbons” refers to hydrocarbon compounds that are found in subterranean reservoirs. Examples of hydrocarbons include oil and gas. As will be apparent from the present description, the nozzles described herein are particularly suited for reservoirs containing heavy oils or similar high viscosity hydrocarbon materials.