Patent ID: 12258832

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed to a method for wellhead workover.

Referring initially toFIG.1, a production tree110and a wellhead120are illustrated. The production tree110is fitted to the wellhead120of a completed well to control production. The production tree110may include a swab valve111, a tree113, a wing valve114(e.g., a production wing valve), a choke115(e.g., a production choke), an upper master valve116, a lower master valve118, and a tubing head adapter119. The swab valve111is the topmost valve on a production tree110that provides vertical access to a wellbore. The tree113couples a production wing112horizontally to the production tree110. The production wing112may include the wing valve114and the choke115. The wing valve114is located on the side of the production tree110. The wing valve114may be used to control and isolate production. The wing valve114may be coupled to a production line (not shown) that further couples the production tree to a production facility. The choke115is a device incorporating an orifice that is used to control fluid flow rate or downstream system pressure.

Further below the production wing112are an upper master valve116, a lower master valve118, and a tubing head adapter119. A master valve controls all flow from the wellbore, and thus a correctly functioning master valve is important. Therefore, two master valves (e.g., the upper master valve116and the lower master valve118) may be used in embodiments. The upper master valve116may be used on a routine basis, and the lower master valve118may provide backup or contingency function in the event that the upper master valve116is leaking and needs replacement. The tubing head adapter119may provide a means of attaching the production tree to the wellhead120. Instead of the two master valve (e.g., the upper master valve116and the lower master valve118) configuration as described above, one master valve may be utilized in embodiments.

Still referring toFIG.1, the wellhead120may include an extended tubing spool122and a corresponding valve123, a first casing spool126and a corresponding first casing valve127. A casing spool (e.g., the first casing spool126) generally secures an upper end of a casing string. During a construction process of a wellbore, casings are lowered in an open hole and cemented in place. For example, casings are run to protect freshwater formations adjacent to the wellbore, isolate a zone of lost returns, or isolate formations with significantly different pressure gradients. A tubing spool (e.g., the extended tubing spool122) generally supports a tubing pipe placed in the casings. For example, the tubing pipe may be a production tubing used to produce reservoir fluids.

In embodiments, the wellhead120may further include a second casing spool124and a corresponding second casing valve125. As shown inFIG.1, the second casing spool124may be disposed below the extended tubing spool122. The second casing spool124may be disposed between the extended tubing spool122and the first casing spool126.

In embodiments, the extended tubing spool122has a vertical length X that is longer than a vertical length of the first casing spool126. A vertical length used herein is defined as a length in a vertical direction between a longitudinal end and an opposite longitudinal end. For example, the vertical length X is a length in the vertical direction between a longitudinal end122aand a longitudinal end122bof the extended tubing spool122. The first casing spool126has a vertical length C1that is a length in the vertical direction between a longitudinal end126aand a longitudinal end126b. The second casing spool124has a vertical length C2that is a length in the vertical direction between a longitudinal end124aand a longitudinal end124b. In embodiments, the vertical length X of the extended tubing spool122may be the same as a combined length of the vertical length C1of the first casing spool126and the vertical length C2of the second casing spool124. In embodiments, the vertical length C1of the first casing spool126may be the same as the vertical length C2of the second casing.

A vertical length Y shown inFIG.1is a vertical length between the first casing spool126and the wing valve114. The length Y is defined by a length between the longitudinal end126band a location of a reference line14of the wing valve114perpendicular to the longitudinal direction of the wellhead120. For example, the reference line14may be a centerline of the wing valve114as shown inFIG.1. Alternatively, the reference line14may be drawn along a bottom end of the wing valve114, or a top end of the wing valve114. The reference line14may be drawn along any parts of the wing valve114as long as the reference line14represents the vertical length Y between the first casing spool126and the wing valve114.

Referring toFIG.2, the production tree110and a wellhead220are illustrated. The production tree110is fitted to the wellhead220of a completed well to control production. The production tree110is the same as the production tree110as described above with reference toFIG.1, and thus the detailed descriptions of the production tree110are omitted. The wellhead220shows the configuration of the wellhead120(FIG.1) after workover is done.

In embodiments, the workover includes decoupling the extended tubing spool122from the wellhead120, coupling a replacement tubing spool222and an additional casing spool224below the replacement tubing spool222, maintaining a consistent vertical length between the first casing spool126and the wing valve114while replacing the extended tubing spool122with the replacement tubing spool222and the additional casing spool224. In embodiments, the replacement tubing spool222has a corresponding valve223, and the additional casing spool224has a corresponding additional casing valve225. A combined length of the replacement tubing spool222and the additional casing spool224are the same as the length of the extended tubing spool122(FIG.1). For example, the combined length of a vertical length X2of the replacement tubing spool222and a vertical length X1of the additional casing spool224is the same as the vertical length X of the extended tubing spool122(FIG.1). The vertical length X1may be a length in the vertical direction between a longitudinal end224aand a longitudinal end224bof the additional casing spool224. The vertical length X2may be a length in the vertical direction between a longitudinal end222aand a longitudinal end222bof the replacement tubing spool222.

In embodiments, the workover may include maintaining a consistent radial direction of the wing valve114while replacing the extended tubing spool122with the replacement tubing spool222and the additional casing spool224. For example, the wing valve114before the workover as shown inFIG.1points toward the same radial direction as the wing valve114after the workover as shown inFIG.2. In other words, the radial direction of the wing valve114does not change after the workover.

In embodiments, the workover may include maintaining connection between the wing valve114and a production line while replacing the extended tubing spool with the replacement tubing spool and the additional casing spool. For example, the production line connects the wing valve114to a production facility.

In embodiments, a length of the additional casing spool224may be the same as a length of the first casing spool126. For example, the vertical length X1is the same as the vertical length C1. In embodiments, a length of the replacement tubing spool222is the same as a length of the first casing spool126. For example, the vertical length X2is the same as the vertical length C1. In embodiments, the first casing spool126, the replacement tubing spool222, and the additional casing spool224may each have the same length. For example, the vertical length C1, the vertical length X1, and the vertical length X2are the same. In embodiments, the length of the additional casing spool224may be the same as a length of the second casing spool124. For example, the vertical length X1is the same as the vertical length C2. In embodiments, the length of the replacement tubing spool222is the same as the length of the second casing spool124. For example, the vertical length X2is the same as the vertical length C2. In embodiments, the second casing spool124, the replacement tubing spool222, and the additional casing spool224may each have the same length. For example, the vertical length C2, the vertical length X1, and the vertical length X2are the same. In embodiments, the length of the first casing spool126, the length of the second casing spool124, the length of the additional casing spool224, and the replacement tubing spool222are the same. For example, the vertical length C1, the vertical length C2, the vertical length X1, and the vertical length X2are the same.

In embodiments, the wellhead220may further include the second casing spool124and the corresponding second casing valve125. As shown inFIG.2, the second casing spool124may be disposed below the additional casing spool224. The second casing spool124may be disposed between the additional casing spool224and the first casing spool126. The first casing spool126and the second casing spool124of the wellhead220are the same as the first casing spool126and the second casing spool124of the wellhead120as described above with reference toFIG.1, and thus the detailed descriptions of the first casing spool126and the second casing spool124are omitted.

It is noted that recitations herein of a component of the present disclosure being “configured” in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references herein to the manner in which a component is “configured” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.

It is noted that the term “the same” utilized herein to include “substantially the same” or “approximately the same.” For the purposes of describing and defining the present invention it is noted that the term “substantially” or “approximately” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” or “approximately” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

Having described the subject matter of the present disclosure in detail and by reference to specific embodiments thereof, it is noted that the various details disclosed herein should not be taken to imply that these details relate to elements that are essential components of the various embodiments described herein, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Further, it will be apparent that modifications and variations are possible without departing from the scope of the present disclosure, including, but not limited to, embodiments defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present invention, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

One or more aspects of the present disclosure are described here.

A first aspect of the present disclosure may be a method including providing a wellhead comprising a first casing spool and an extended tubing spool disposed above the first casing spool, and a production tree comprising a wing valve disposed above the extended tubing spool. The method further includes decoupling the extended tubing spool from the wellhead, coupling a replacement tubing spool and an additional casing spool below the replacement tubing spool to the wellhead replacing the extended tubing spool. A combined length of the replacement tubing spool and the additional casing spool is the same as the length of the extended tubing spool. The method further includes maintaining a consistent vertical length between the first casing spool and the wing valve while replacing the extended tubing spool with the replacement tubing spool and the additional casing spool.

A second aspect of the present disclosure may include the first aspect, wherein the method further includes maintaining a consistent radial direction of the wing valve while replacing the extended tubing spool with the replacement tubing spool and the additional casing spool.

A third aspect of the present disclosure may include the first aspect or the second aspect, wherein the method further includes maintaining connection between the wing valve and a production line while replacing the extended tubing spool with the replacement tubing spool and the additional casing spool.

A fourth aspect of the present disclosure may include the any of the first through third aspects, wherein a length of the additional casing spool is the same as a length of the first casing spool.

A fifth aspect of the present disclosure may include the any of the first through fourth aspects, wherein a length of the replacement tubing spool is the same as a length of the first casing spool.

A sixth aspect of the present disclosure may include the any of the first through fifth aspects, wherein the first casing spool, the replacement tubing spool, and the additional casing spool have the same length.

A seventh aspect of the present disclosure may include the any of the first through sixth aspects, wherein the wellhead further comprises: a second casing spool disposed below the extended tubing spool, wherein the length of the extended tubing spool is the same as a combined length of the first casing spool and the second casing spool.

An eighth aspect of the present disclosure may include the any of the first through seventh aspects, wherein the second casing spool, the replacement tubing spool, and the additional casing spool have the same length.

A ninth aspect of the present disclosure may include the any of the first through eighth aspects, wherein the second casing spool and the first casing spool have the same length.