CA2633126A1

CA2633126A1 - Heated stuffing box with fluid containment

Info

Publication number: CA2633126A1
Application number: CA002633126A
Authority: CA
Inventors: Perry St. Denis
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-11-30
Also published as: CA2726332A1; US20110139436A1; WO2009143617A1

Abstract

A heated stuffing box includes a housing having an outer surface, an inner surface defining a packing-receiving bore, a lower surface for attaching to a wellhead and an upper surface. A flow passage through the housing for passing temperature-conditioned fluid through the housing, the flow passage having an input and an output.

Description

TITLE
[0001] Heated stuffing box with fluid containment FIELD

[0002] A stuffing box for a wellhead that is heated.
BACKGROUND

[0003] A stuffing box is a packing gland chamber used to hold packing material compressed around a moving pump rod to reduce the escape of fluids from a well. Instead, the well fluids are directed to a production line. In cold temperatures, stuffing boxes may begin to leak well fluids, the grease or oil may become less viscous, and the well head may freeze.

SUMMARY

[0004] There is provided a heated stuffing box, comprising a housing having an outer surface, an inner surface defining a packing-receiving bore, a lower surface for attaching to a wellhead and an upper surface. A flow passage through the housing for passes temperature-conditioned fluid through the housing, the flow passage having an input and an output.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
FIG. 1 is a side elevation view in section of a heated stuffing box. with containment.
FIG. 2 is a side elevation view in section of a heated stuffing box attached to a wellhead.
FIG. 3 is a side elevation view in section of a heated stuffing box without containment.
FIG. 4 is a top plan view of a heated stuffing box showing the containment cavity and vertical passages for the heated jacket.
FIG. 5 is a side elevation view in section of a heated stuffing box with possible dimensions for one embodiment.
FIG. 6 is a partially transparent bottom plan view showing a passage of the heated jacket connecting two vertical passages.
FIG. 7 is a side elevation view in section of a heated stuffing box. showing details of the test cock and passages of the heated jacket.
FIG. 8 is a perspective view in section of a heated stuffing box.
FIG. 9 is a side elevation view in section of a heated stuffing box showing the input and output passages of the heated jacket.

DETAILED DESCRIPTION

[0006] A heated stuffing box generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 8.

Structure and Relationship of Parts:

[0007] In cold temperatures, the stuffing boxes tend to leak well fluids. It has been found that one of the causes of this leakage is that, as the packing gland in a stuffing box becomes cold, it does not compress around the polish rod. In addition, in cold temperatures, the lubricant, such as grease or oil, may also be come stiff and less effective. Furthermore, most wells in cold weather will freeze at the well head, including the stuffing box. By using a heated stuffing box as described herein, this effect can be prevented, or at least reduced, resulting in less spillage and torn packing glands in the stuffing box.

[0008] FIG. 2 shows the heated stuffing box housing on a typical wellhead, flanged above a flow-tee of a wellhead. Below the flow-tee are the polish rod lock-out, or radigan blowout preventer. Below that is the wellhead tubing bonnet. Above the stuffing box is a driver that drives the polish rod. It will be understood that the stuffing box may be adapted to be used with polish rods that rotate or that reciprocate, and that the driver may therefore be a drive head that rotates the polish rod, or a pumping jack the reciprocates the rod vertically.

[0009] As the drive head or jack causes fluids to be pumped from the well, the fluids come up the well into the wellhead, and exit through the flow-tee. The packing glands of the stuffing box seal against the polish rod to prevent fluid from flowing up through the stuffing box. The stuffing box is preferably provided with a lantern spring to compress the stuffing as it wears. A plate is bolted over the spring and the packing gland cavity to enclose the packing. A cavity is located at the top of the stuffing box above the plate that containst eh stuffing and where the polish rod exits the packing glands. The driver or another plate may be bolted on top to form a containment chamber with the cavity to contain any fluids that leak through the packing glands. As the chamber fills with fluid, it may be piped to a holding system through a test cock.

[0010] The housing of the stuffing box is formed to have a "heated jacket", with an input and an output for heated fluid to flow through, such as heated water, steam, oil, etc. The heated fluid may be used to maintain the packing gland at a constant temperature, which may also include acting as a cooling fluid, if necessary. The jacket may be formed by machining passages into the housing, and connecting the various passages to create a flow path that flows around the packing glands in the body. This may be done by having a series of inputs and outputs that connect the passages externally, or preferably, by sealing the holes at the surface of the housing while leaving the adjacent channels connected inside the housing. The channels may be formed vertically as well as horizontally to achieve a higher coverage. For example, FIG. 5 and 6 show passages that pass around the stuffing box, while FIG. 7 shows vertical passages that connect these passages. Since the passages are made by machining from the surface, the outside of these passages are filled to prevent fluid from escaping.

[0011] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0012] The following claims are to understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted.
Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims.
The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described.

Claims

1. A heated stuffing box, comprising:
a housing having an outer surface, an inner surface defining a packing-receiving bore, a lower surface for attaching to a wellhead and an upper surface; and a flow passage through the housing for passing temperature-conditioned fluid through the housing, the flow passage having an input and an output.

2. The heated stuffing box of claim 1, wherein the housing has a containment chamber positioned toward the upper surface of the housing relative to the packing-receiving bore.

3. The heated stuffing box of claim 2, wherein the containment chamber is formed from a cavity in the upper surface, and a driver attached to the upper surface.

4. The heated stuffing box of claim 1, wherein the housing is a unitary piece of material, and the flow passage is formed from a series of connected machined passages.