Patent Application
20160040505
1. Field of the Disclosure
The present invention is related to a high efficiency nozzle and, in particular, a high efficiency nozzle to clean equipment in a wellbore.
2. Background of the Art
Various downhole operations, such as milling, etc., create debris and particles that circulate and settle within the wellbore. In certain applications, such debris and particles negatively affect wellbore equipment such as blow out preventers and other equipment. In such applications, cleaning operations are performed to remove debris from wellbore equipment and generally clean wellbore walls. However, most current wellbore cleaning apparatuses, including traditional nozzles, induce turbulence, that causes the stream to disperse and lose energy rapidly. Accordingly, current wellbore cleaning apparatuses may not provide sufficient velocity and force to remove debris and particles, diminishing cleaning effectiveness, leading to slow or incomplete cleaning operations.
In one aspect, the present disclosure provides a nozzle including an inlet; an outlet; at least four successive concentric stages in fluid communication with the inlet and the outlet, where the at least four stages each have a discrete length and a successively smaller discrete diameter; and a plurality of interfaces formed between each of the stages.
In another aspect, the present disclosure provides a system to clean a wellbore, including a work string; and a jet sub containing at least one nozzle, wherein the at least one nozzle includes: an inlet; an outlet; at least four successive concentric stages in fluid communication with the inlet and the outlet, where the at least four stages each have a discrete length and a successively smaller discrete diameter; and a plurality of interfaces formed between each of the stages.
Examples of certain features of the apparatus and method disclosed herein are summarized rather broadly in order that the detailed description thereof that follows may be better understood. There are, of course, additional features of the apparatus and method disclosed that will form the subject of the appended claims.
This disclosure is best understood by the accompanying figures:
In an exemplary embodiment, the wellbore cleaning tool or jet sub 110 is conveyed to a selected depth of the wellbore 102 by the workstring 106. In certain embodiments, the wellbore cleaning tool 110 is conveyed to be adjacent to wellbore equipment 108 to be cleaned. Wellbore equipment 108 includes any equipment placed downhole, such as, blow out preventers. Particularly, after milling of casing 104 or other operations, particles and debris circulate within the wellbore 102, requiring removal of such particles and debris to ensure proper operation of wellbore equipment 108. The tool 110 includes one or more nozzles 112 to facilitate flow of a cleaning fluid flow 114 within the wellbore 102 and particularly within equipment 108. Multiple nozzles 112 may be included to facilitate flow of cleaning fluid flow 114. Flow from nozzles 112 may flow outward into equipment 108 and afterwards move upward or downward within wellbore 102 removing particles and debris. Tool 110 may be translated within the wellbore 102 and rotated to ensure cleaning of the wellbore 102 and wellbore equipment 108. Fluid flow 114 may include completion fluid such as salt water with polymer particulate, mud, or produced fluids. Details of the tool 110 and nozzle 112 are discussed below with respect to
Inlet 322, outlet 324 and stages 330 are all concentrically formed with an axis 326. In an exemplary embodiment, nozzle 312 includes multiple stages 330. The stages 330 are in fluid communication with each other and are concentrically aligned along axis 326. Each stage 330 is generally cylindrically shaped with a length 332, a diameter 334, and an interface 336 between stages 330. Nozzle 312 may have at least three, four, or more successive concentric stages 330.
The length 332 and diameter 334 of each stage 330 may vary. In certain embodiments, the length 332 for each stage 330 may be the same or similar. In an exemplary embodiment, the diameter 334 of each successive stage 330 is smaller as the flow moves closer to the outlet 324, constricting in size to increase flow velocity as it passes through stages 330. The diameter 334 of each stage 330 is a discrete diameter, separate from a diameter 334 of another stage 330.
In between successive steps 330 an interface 336 is formed. Interface 336 is formed at the abutment of two successive stages 330 with different stage diameters 334. This interface 336 may also be referred to as a step. In an exemplary embodiment, the nozzle 312 may have at least two interfaces 336 located between the at least three stages 330. Interface 336 may have a slope or angle to assist the transition of flow 114 from a larger stage 330 to a smaller stage 330. In an exemplary embodiment, the interface angle is 15 degrees to 100 degrees. In certain embodiments, the angle is 45 degrees.
In an exemplary embodiment, a relationship or ratio is formed between the height of interface 336 and a respective stage length 332. In an exemplary embodiment, the ratio between the height of interface 336 and respective stage length 332 is between 3 to 1 and 20 to 1. In certain embodiments, the ratio is 10 to 1. Furthermore, in exemplary embodiments, the ratio between the height of interface 336 and respective stage length 334 may be the same for all stages.
Due to the characteristics of the stages 330, less energy loss and less turbulence is experienced compared to traditional nozzles. The use of at least 3 discrete steps or stages 330 and at least two interfaces 336 allows for less turbulence to propagate along the length of the nozzle 312 while increasing the velocity of the flow 114. In an exemplary embodiment, the nozzle 312 has a 99.5% efficiency, compared to traditional nozzles that may only have a 98.5% efficiency. As a result, the flow 114 to exit the nozzle 312 has less turbulence and internal circulation, allowing for higher velocity and longer travel, with minimal dispersion and velocity fall off. Accordingly, fluid friction of the flow 114 beyond the nozzle 312 is minimized and cleaning performance is increased.
Therefore in one aspect, the present disclosure provides a nozzle including an inlet; an outlet; at least four successive concentric stages in fluid communication with the inlet and the outlet, where the at least four stages each have a discrete length and a successively smaller discrete diameter; and a plurality of interfaces formed between each of the stages. In various embodiments, a ratio between at least one length of the at least four lengths and at least one height of at least one respective interface of the plurality of interfaces is at least 3 to 1. In certain embodiments, a ratio between at least one length of the at least four lengths and at least one height of at least one respective interface of the plurality of interfaces is not greater than 20 to 1. In various embodiments, at least one interface of the plurality of interfaces has an angle of at least 15 degrees. In various embodiments, at least one interface of the plurality of interfaces has an angle not greater than 100 degrees. In certain embodiments, each of the at least four lengths is the same. In certain embodiments, a height of each of the plurality of interfaces is the same. In certain embodiments, a ratio between each of the at least four lengths and a height of each of the plurality of interfaces is the same. In various embodiments, an angle of each of the plurality of interfaces is the same.
In another aspect, the present disclosure provides a system to clean a wellbore, including: a work string; and a jet sub containing at least one nozzle, wherein the at least one nozzle includes: an inlet; an outlet; at least four successive concentric stages in fluid communication with the inlet and the outlet, where the at least four stages each have a discrete length and a successively smaller discrete diameter; and a plurality of interfaces formed between each of the stages. In certain embodiments, a ratio between at least one length of the at least four lengths and at least one height of at least one respective interface of the plurality of interfaces is not greater than 20 to 1. In various embodiments, at least one interface of the plurality of interfaces has an angle of at least 15 degrees. In various embodiments, at least one interface of the plurality of interfaces has an angle not greater than 100 degrees. In certain embodiments, each of the at least four lengths is the same. In certain embodiments, a height of each of the plurality of interfaces is the same. In certain embodiments, a ratio between each of the at least four lengths and a height of each of the plurality of interfaces is the same. In various embodiments, an angle of each of the plurality of interfaces is the same.
In another aspect, the present disclosure provides a method for cleaning a wellbore, including: conveying a work string in a wellbore; providing a jet sub associated with the wellbore, wherein the jet sub includes at least one nozzle, the nozzle including: an inlet; an outlet; at least four successive concentric stages in fluid communication with the inlet and the outlet, where the at least four stages each have a discrete length and a successively smaller discrete diameter; and a plurality of interfaces formed between each of the stages; providing a completion fluid to the at least one nozzles via the work string and jet sub; and expelling the completion fluid via the at least one nozzles. In various embodiments, a ratio between at least one length of the at least four lengths and at least one height of at least one respective interface of the plurality of interfaces is at least 3 to 1. In certain embodiments, a ratio between at least one length of the at least four lengths and at least one height of at least one respective interface of the plurality of interfaces is not greater than 20 to 1. In various embodiments, at least one interface of the plurality of interfaces has an angle of at least 15 degrees. In various embodiments, at least one interface of the plurality of interfaces has an angle not greater than 100 degrees. In certain embodiments, a ratio between each of the at least four lengths and a height of each of the plurality of interfaces is the same. In certain embodiments, the expelled completion fluid allows for effective cleaning at a 20% further distance compared to conventional methods. In other certain embodiments, the expelled completion fluid allows for reduced fluidic drag compared to conventional methods.
While the foregoing disclosure is directed to the certain exemplary embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure.
