Patent Application
20170226818
In the course of producing oil and gas wells, typically after the well is drilled, the well may be completed. One way to complete a well is to divide the well into several zones and then treat each zone individually. Treating each section of the well individually may be accomplished in several ways.
One commonly used way of accessing the area to be treated is referred to as plug and perf. Generally, when plug and perf is used a perforating assembly is prepared on the surface. The perforating assembly typically consists of a plug on the lower end of the assembly, a setting tool just above the plug, and a perforating gun just above the setting tool. The assembly is then run into the wellbore to some point below the first zone that the operator desires to treat. The setting tool is then activated locking the plug into place and sealing the well below the plug against fluid flow from the surface or the well above the plug. The setting tool is then disconnected from the plug allowing the setting tool in the perforating gun to be moved to a point adjacent the first zone that the operator desires to treat. The perforating gun is then activated penetrating the casing to allow access to the first zone. The process is then repeated to allow access to each additional zone. One of the difficulties with the plug and perf method of accessing the zones is that is time intensive which in times of rig scarcity vastly increases the cost of the plug and perf method.
Another commonly used method of accessing the area to be treated is to assemble a tubular assembly on the surface where the tubular assembly has a series of spaced apart sliding sleeves. Sliding sleeves are typically spaced so that at least one sliding sleeve will be adjacent to each zone. In some instances, annular packers may also be spaced apart along the tubular assembly in order to divide the wellbore into the desired number of zones. The tubular assembly is then run into the wellbore typically with the sliding sleeves in the closed position. In instances when annular packers are not used to divide the wellbore into the desired number of zones the tubular assembly may be cemented in place.
Once the tubular assembly is in place in the well and has been cemented in place or the packers have been actuated each of the sliding sleeves are opened in turn. To open a sliding sleeve, an obturator, such as a ball, a dart, etc., is dropped into the wellbore from the surface and pumped through the tubular assembly. The obturator is pumped through the tubular assembly to the sliding sleeve where it lands on the seat of the sliding sleeve and forms a seal with the seat on the sliding sleeve to block all further fluid flow past the ball and the seat. As additional fluid is pumped into the well the differential pressure formed across the seat and ball provides sufficient force to move the sliding sleeve from its closed position to its open position. Fluid may then be pumped out of the tubular assembly and into the formation so that the formation may be treated.
The use of sliding sleeves to access the well tends to avoid the time issue of the plug and perf method however the use of sliding sleeves tends to reduce the volume of fluid that may flow upward through the wellbore at any given time. The reduced volume of fluid that is able to flow through the wellbore is due to the varying sizes of the balls required to activate each individual sliding sleeve. Specifically, in order to individually activate a sliding sleeve each sliding sleeve requires its own ball size such that the smallest ball and consequently the smallest diameter seat is located at the lower end of the well and each subsequent ball, to activate the next higher sliding sleeve within the wellbore, is slightly larger than the ball used to activate the sliding sleeve below. Therefore, the amount of fluid that can flow through the lowest seat in the lowest sliding sleeve is reduced.
In an embodiment of the present invention a unique counting system is utilized allowing multiple balls to pass through the counting mechanism while activation of a sliding sleeve is delayed until the appropriate number of balls have passed through. By counting the number of balls passing through rather than using various sizes of balls as in a typical sliding sleeve arrangement, reductions in the inner diameter of the wellbore tubular are avoided. The counting sliding sleeve allows the wellbore tubular to remain relatively uniform in inner diameter avoiding any reduced flow past a particular sliding sleeve. The time costs of plug and perf are also avoided by utilizing a ball system so that the operator does not need to run in and out of the well to access each formation.
At the top of the counting sliding sleeve 10, is a top sub 12, a shear ring assembly 14, and ports 16. The shear ring assembly 14 could be a shear pin, a shear ring, snap ring, etc.
A counting sliding sleeve 10 is limited to a maximum number of counts only in relation to the diameter of a particular tool.
It can be seen that spinner sleeve 40 has a number of buttons 80 about the interior circumference of spinner sleeve 40. While even a single button 80 would allow the spinner sleeve 40 to function, multiple buttons 80 are preferred. In the spinner sleeves 40 initial position each button 80 is supported, prevented from moving radially outward, by the outer housing 52 such that after a ball passes through the collet 22 it moves into the interior of the spinner sleeve 40 and interacts with buttons 80. The buttons 80 in their supported position do not allow the ball to pass through. With the ball supported on buttons 80, pressure may be applied from the surface against ball 80 and thereby to spinner sleeve 40 causing spinner sleeve 40 to move downward. As spinner sleeve 40 moves downward the spinner sleeve 40 is rotated one halfstep as described below. Additionally, as spinner sleeve 40 moves downward, buttons 80 move to a position relative to the outer housing 52 such that the buttons 80 are allowed to move radially outward into recess 82 within outer housing 52. As the buttons move radially outward into recess 82 the ball is released allowing the ball to pass through the interior of spinner sleeve 40. Once the ball has been released the downward force upon spinner sleeve 40 is removed allowing biasing device 50 to push the spinner sleeve 40 upwards. As spinner sleeve 40 moves upwards the torsional biasing device 60 as well as the interaction between pin 62 and slot 64, force the spinner sleeve 40 to rotate a second halfstep. With the first halfstep and the second halfstep completed the spinner sleeve is back in its initial, albeit slightly rotated, position provided the spinner sleeve 40 has not reached the end of its count, the spinner sleeve 40 is now ready to accept the next ball that passes through the interior of the tubular.
In the event that spinner sleeve 40 does reach the end of its count, where the count is the interaction between the slots 64 and pins 62, the spinner sleeve 40 moves upwards an additional distance upward such that the upper end 84 of spinner sleeve 40 moves into recess 54. With the upper end 84 of spinner sleeve 40 within recess 54 the distal ends 37 of the collet fingers 34 and 36 are now supported. The next properly sized obturating object such as a ball (not shown) that reaches the counting sliding sleeve 10 will land on the now supported distal ends 37 of the collet fingers such as 34 and 36 and form a seal with the inner collet elastomer element 36 allowing pressure to be applied against the ball from the surface. With pressure applied from the surface the shear device such as shear ring 14 is overcome allowing sleeve 56 to move downward within spinner sleeve 40 until the distal ends 37 of the collet fingers and the outer collet elastomer element 38 reach and seal against shoulder 42 within spinner sleeve 40. Once the collet fingers and outer collet elastomer element 38 seat against shoulder 42 within spinner sleeve 40 both the spinner sleeve 40 and the sleeve 56 continue downward in response to pressure applied from the surface against the ball. As the sleeve 56 and spinner sleeve 40 are moved downward ports 16 are uncovered allowing fluid access from the interior of the spinner tool 10 through the housing 52. An anti-reverse lock 44 such as spring-loaded C ring, a spring-loaded pin, or the depicted snap ring sits in a recess or slot 46. The anti-reverse lock 44 is provided to hold the sleeve 56 open when sleeve 56 moves downward. As the snap ring 44 reaches recess 54 the snap ring will expand radially outward into recess 54 thereby preventing the interior sleeve 56 from re-closing which in turn would prevent fluid access from the interior of the spinner tool 10 through ports 16.
The distance between the seals 18 and 20 on either side of the ports 16 in order to isolate the ports 16 is minimized in order to decrease the overall length of the tool.
The collet 22 flexes allowing the ball (not shown) to pass through. The seat is initially unsupported such that when the ball reaches the collet 22 the collet fingers, such as collet fingers 34 and 36 flex outwards so as to minimally impede the balls passage past the collet. The housing 52 has a recess 54 to allow the distal end 37 of the collet fingers, such as collet finger 34 and 36, to expand radially outward thereby allowing a properly sized obturator to move past the distal end 37 of the collet 22.
Typically, the outer collet elastomer element 38 is constructed such that when collet 22 is forced downward into spinner sleeve 40 the outer collet elastomer element 38 will seat against shoulder 42 and in conjunction with the collet fingers distal and such as collet fingers 34 and 36, inner collet elastomer element 36, and the obturating object such as a ball (not shown) will form a seal to prevent fluid flow past collet 22.
In certain instances is been found advantageous to cut the elastomer 32 or more specifically the inner collet elastomer element 36 and the outer collet elastomer element 38 between each of the collet fingers such as fingers 34 and 36. Additionally it has been found that cutting or forming the distal ends 37 of the collet fingers such as collet fingers 34 and 36 at both a radial angle and an axial angle so that when in obturating object attempts to force the collet fingers 34 and 36 radially outward, the force provided by the obturating object against the collet fingers tends to lock any elastomer between the collet fingers such as collet fingers 34 and 36 in place forming an enhanced seal.
The collet 22 is provided with an elastomer on the inside, an elastomer on the outside, and the scarf cut collet fingers include an elastomer between the collet fingers. The scarf cut is located at the distal ends 37 of the collet fingers, such as collet fingers 34 and 36, and are cut or formed at both a radial angle and an axial angle such that when the fingers are compressed radially outward elastomer between the fingers is compressed forming an enhanced seal.
As shown in
It is envisioned that the tool or components thereof may be built from steel, aluminum, cast iron, composite, erodible material, dissolvable material, etc.
While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible.
Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.
This application claims priority to U.S. Provisional Patent Application No. 62/291,366 that was filed on Feb. 4, 2016.
| Number | Date | Country | |
|---|---|---|---|
| 62291366 | Feb 2016 | US |
