Patent Application
20190040703
This disclosure relates to wellbore drilling and completions and, for example, to optimizing casing installation within the wellbore.
When completing a production or injection wellbore, casing can sometimes be installed to line the walls of the wellbore. Casing can include steel piping with an outer diameter that is less than the diameter of the wellbore. The casing can help provide structural support to the wellbore and seal the wellbore from parts of the geologic formation in which the wellbore has been formed.
Installing casing involves running long strings of pipe, also known as casing strings, through at least a portion of a wellbore, from a topside facility. While the casing string is being run, fluid can be circulated through the casing string and up through the annulus formed between the outer surface of the casing string and the inner wall of the wellbore. The circulating fluid helps provide static pressure on the geologic formation to prevent a “kick” from the wellbore, or releasing pressurized hydrocarbons to the environment.
Once the casing has reached a target depth within the wellbore, cement can be circulated similarly to the previously circulated fluid. The cement hardens in the annulus and secures the casing in place. The cement can also act as an added layer of protection between the wellbore and the geologic formation.
This disclosure describes technologies relating to vibration-induced installation of wellbore casing.
An example implementation of the subject matter described within this disclosure is a wellbore casing shoe vibration assembly with the following features. An unbalanced sub-assembly is located within the wellbore casing shoe. The unbalanced sub-assembly includes a turbine and a shaft coupled to the turbine at a first end of the shaft. The unbalanced sub-assembly is configured to rotate and to impart a vibration to the casing in response to a fluid being passed through the casing. A rupture disc is positioned on one end of the unbalanced sub assembly. The rupture disc is configured to rupture above a specified differential pressure threshold caused by fluid flowing through the vibration assembly. The rupture disc is configured to allow the fluid to bypass the unbalanced sub assembly when the rupture disc is in a ruptured state. The rupture disc is configured to direct fluid through the unbalanced sub assembly when the rupture disc is in an un-ruptured state.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The shaft is an unbalanced shaft that has an uneven weight distribution along a longitudinal axis of the shaft. The turbine and the unbalanced shaft are configured to rotate in response to the fluid being passed through the casing. The rotating, unbalanced shaft imparts the vibration to the casing.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The unbalanced shaft further includes a rotary bar coupled to and rotatable with the turbine. The rotary bar includes a first axial portion of a first outer diameter and a second axial portion of a second outer diameter attached end-to-end with the first axial portion. The first outer diameter is different from the second outer diameter. A rotation of the rotary bar with the turbine imparts a vibration to the casing.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The turbine is a first turbine. The vibration assembly further comprising a second turbine positioned at a second end of the unbalanced shaft than the first turbine.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The turbine, the unbalanced shaft, and the rupture disc are configured to be drilled out after use.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The turbine is configured to reduce a rotational speed when the rupture disc is in the ruptured state.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The fluid passing through the turbine includes drilling fluid or cement.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. A rotational speed sensor is positioned in an outer housing of the vibration assembly. The rotational speed sensor is configured to detect a rotational speed of the turbine. A first hydrostatic pressure sensor is positioned in the outer housing of the vibration assembly. The first hydrostatic pressure sensor is configured to measure a static pressure within the casing. A second hydrostatic pressure sensor is positioned in the outer housing of the vibration assembly. The second hydrostatic pressure sensor is configured to measure a static pressure of an annulus between an outer surface of the casing and an inner surface of the wellbore. A controller is positioned in the outer housing of the vibration assembly. The controller is configured to receive, process, and transmit data received from the rotational speed sensor, the first hydrostatic pressure sensor and the second hydrostatic pressure sensor. A battery is positioned in the outer housing of the vibration assembly. The battery is configured to impart electrical energy to the controller, rotational speed sensor, the first hydrostatic pressure sensor, and the second hydrostatic pressure sensor.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. A generator is coupled to the turbine. The generator is configured to charge the battery.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. A temperature sensor is configured to measure a temperature of the annulus between an outer surface of the casing and an inner surface of the wellbore.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The controller is configured to determine a casing leak based on a signal from the first hydrostatic pressure sensor and a signal from the second hydrostatic pressure sensor.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The controller is configured to diagnose a failure in the rotational speed sensor, the first hydrostatic pressure sensor, or the second hydrostatic pressure sensor.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The controller is configured to wirelessly transmit a status of the vibration assembly to a topside facility.
Aspects of the example implementation, which can be combined with the example implementation alone or in combination, include the following. The rotational speed sensor, the first hydrostatic pressure sensor, the second hydrostatic pressure sensor, the controller, and the battery are all configured to remain within the outer housing of the vibration assembly after the casing string is installed.
An example implementation of the subject matter described within this disclosure is a method of installing a casing string into a wellbore with the following features. While running a casing string to a target depth within a wellbore, a coefficient of friction between the casing string and the wellbore is reduced by inducing a vibration within the casing string by activating a vibration inducing device positioned within a shoe at a downhole end of the casing string. An annulus is defined between the casing string and the wellbore. A closed fluid bypass channel positioned within the vibration inducing device. A fluid is flowed through the casing string. The fluid passes through the vibration inducing device. The closed fluid bypass channel is closed to flow of the fluid through the fluid bypass channel. In response to an increase in a differential pressure of the fluid resulting from an increased flow of the fluid within the casing, the fluid bypass channel is opened. At least a portion of the fluid flows through the opened fluid bypass channel, and a remainder of the fluid flows through the vibration inducing device causing a change in the vibration induced within the casing string. The fluid is flowed through the annulus while the casing string vibrates at the changed vibration induced within the casing string.
Aspects of the example method, which can be combined with the example method alone or in combination, include the following. After setting the casing string at the target depth and after flowing the fluid through the annulus the vibration inducing device is drilled through prior to starting production through the casing string.
Aspects of the example method, which can be combined with the example method alone or in combination, include the following. A status of the vibration inducing device is sent wirelessly to a topside facility. The status includes a rotational speed of the vibration inducing device, a static pressure within the casing, and a static pressure within the annulus.
Aspects of the example method, which can be combined with the example method alone or in combination, include the following. Wirelessly sending the status includes transmitting radio waves to the topside facility.
Aspects of the example method, which can be combined with the example method alone or in combination, include the following. Opening a bypass includes rupturing a rupture disc. The rupture disc is configured to rupture when a differential pressure across the vibration inducing device goes above a specified threshold.
Aspects of the example method, which can be combined with the example method alone or in combination, include the following. The vibration inducing device includes a turbine. Inducing a vibration includes inducing rotation in an unbalanced shaft that defines the bypass channel. The unbalanced shaft is coupled to the turbine. The bypass channel is configured to divert at least a portion of the flow away from the turbine.
An example implementation of the subject matter described within this disclosure is a wellbore casing installation method with the following feature. While running a casing string to a target depth within a wellbore, a coefficient of friction is reduced between the casing string and the wellbore by inducing a vibration within the casing string by activating a vibration inducing device positioned within a shoe at a downhole end of the casing string. An annulus is defined between the casing string and the wellbore. The vibration inducing device includes a turbine positioned within the shoe. The turbine is configured to rotate in response to a fluid flow passing through the casing joint during installation operations. An unbalanced shaft defines a bypass flow path. The unbalanced shaft is coupled to the turbine. The unbalanced shaft is configured to impart a vibration to the casing as the turbine rotates. A rupture disc is positioned on one end of the unbalanced shaft. The rupture disc is configured to rupture above a specific pressure differential threshold caused by the fluid flow across the turbine. The rupture disc is configured to allow at least a part of the fluid flow through the bypass flow path when the rupture disc is in a ruptured state. The rupture disc is configured to direct the fluid flow through the turbine when the rupture disc is in an un-ruptured state. The turbine is configured to rotate at a lower rotational speed when the disc is in the ruptured state. A fluid is flowed through the casing string to induce a vibration. The fluid passes through the vibration inducing device. The bypass flow path is closed to flow of the fluid through the bypass flow path. In response to an increase in a differential pressure of the fluid resulting from an increased flow of the fluid within the casing, the bypass flow path is opened. At least a portion of the fluid flows through the opened fluid bypass flow path, and a remainder of the fluid flows through the vibration inducing device causing a change in the vibration induced within the casing string.
The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.
Like reference numbers and designations in the various drawings indicate like elements.
When installing a casing string into a wellbore, especially long, horizontal, or deviated wellbores, friction between the casing string and the walls of the wellbore can make installation difficult or impossible. In some instances, wellbore tractors can be deployed to pull the casing through the wellbore, but tractors cannot always be used in certain situations. For example, string weight, hole tortuosity, debris buildup in the open-hole, clay-swelling, or hole collapse can prevent the use of a tractor. If a tractor cannot be used, the wellbore can sometimes be re-drilled or reamed, but both options present high cost and extend the time needed to complete the wellbore. In some cases, neither re-drilling nor re-reaming can be done.
In addition, once the casing has reached its target depth, cementing the casing and ensuring an even distribution of cement can be a challenge. If a cement job is not satisfactorily completed, that is, the cement is not evenly distributed, cured, or bonded, then the entire cased section can need to be plugged and re-drilled. In some instances, the casing is perforated and an attempt is made to pump cement into problem areas. Any of the previously mentioned operations can cause extreme delays in completing the wellbore.
This disclosure relates to a smart vibration assembly that can be added to a casing shoe during installation for the purposes of reducing the apparent friction between the casing and the wellbore, and aid in compacting and distributing cement during cementing operations. The vibration assembly is powered by fluid, such as cement, drilling mud, or other fluids, flowing through a turbine and rotating an unbalanced component to produce vibrations. The vibration components are constructed from drillable materials so that the vibration components can be “drilled out” and removed after installation is complete. The assembly also contains sensors and communication equipment that can monitor pressure within the assembly, pressure within the annulus, RPMs of the turbine, internal flow, and any other pertinent parameters. In some implementations, the sensors and communication equipment are positioned within the housing and are not drilled-out after installation. The communication equipment is able to relay information back to a topside facility wirelessly. The assembly also includes a bypass that can be activated by bursting a rupture disc. The bypass can allow for low-frequency vibrations at high flow rates.
The casing string 112 can include a vibration assembly 102 within a shoe 101 at a downhole end of the casing string 112. The vibration assembly 102 can help distribute cement more efficiently around the shoe joint in order to have a competent cement isolation at the shoe. Normal operations include a shoe test, Formation Integrity Test (FIT), or both, prior to drilling the next section. It is important to have a competent cement sheath surrounding the shoe joint. The vibration assembly 112 can be coupled directly to, the casing string, the shoe, or both. In general the system is able to evaluate the integrity of the casing shoe after cement job, to verify the presence of cement around the casing shoe, identify possible losses around the casing shoe, and evaluate the quality of cement job around the shoe. In some instances, the vibration assembly 102 can help improve the quality of cementing job (bond) around the shoe track and hat-hole. In some instances, the vibration assembly 102 can enhance operational safety due to early detection on cement job evaluation
The vibration assembly 102 is powered by the fluid flowing through the casing string 112. While the illustrated implementation shows the casing string 112 being installed in a vertical wellbore, the system can also be utilized in a deviated or horizontal wellbore. Aspects of this disclosure can be applied to either production or injection wellbores.
The shaft 210 is hollow and defines a fluid flow pathway along its longitudinal axis. In some implementations, the shaft 210 is an unbalanced shaft that has an uneven weight distribution along the longitudinal axis of the shaft 210. For example, the shaft 210 can include end portions of a first diameter and a center portion between the end portions of a second diameter different from (that is, less than or more than) the first diameter. Starting from a shaft having a substantially constant diameter along its longitudinal axis, some material can be removed from the center portion to reduce that portion's diameter relative to the remainder of the shaft. Alternatively, the shaft can be formed into an unbalanced shaft by removing portions from one or both end portions or the center portion and one of the end portions. In some implementations, the length of the shaft can be divided into two portions and material can be removed from one of the two portions to form the unbalanced shaft.
The turbine and the unbalanced shaft rotate in response to the fluid being passed through the casing. The uneven weight distribution along the longitudinal axis induces a vibration in the shaft as the shaft rotates. In this manner, the rotating, unbalanced shaft imparts the vibration to the downhole end of the casing. In some implementations, the unbalanced shaft includes a rotary bar coupled to, and rotatable with, the turbine 220. The rotary bar includes a first axial portion 210a of a first outer diameter and a second axial portion 210b of a second outer diameter, attached end-to-end with the first axial portion. The first outer diameter is different from the second outer diameter. This offset causes the rotation of the rotary bar with the turbine 220 to impart a vibration to the casing. In some implementations, a third axial portion 210c can be included with the rotary bar. The third portion 210c can be axially aligned with the first axial portion 210a. In some implementations, a weight can be added to the rotary bar to provide at least a portion of the imbalance. While the illustrated implementation shows an unbalanced shaft 210 as the source of vibration, some implementations can include an imbalanced turbine to produce a similar affect.
In the illustrated implementation, a rupture disc 202 is positioned on one end of the unbalanced sub assembly 200, for example, on an uphole end of the unbalanced shaft 210 to seal that end of the shaft 210. The rupture disc is designed to rupture (that is, burst or break to an extent that fluid can flow through the ruptured disc) above a specified differential pressure threshold caused by fluid flowing through the vibration assembly. The rupture disc 202 can include a ceramic material, a metal alloy, or any other drillable material. The rupture disc 202 is designed to rupture instantly when the specified differential pressure threshold is reached. The rupture disc 202 is either in the ruptured state, or in an un-ruptured state. There is no practical transition period between states.
When the rupture disc is in an un-ruptured state, the rupture disc directs fluid through the unbalanced sub assembly 200 and blocks the flow of fluid through the shaft 210. Specifically, for the illustrated example, the rupture disc directs the entirety of the fluid flow through at least one of the turbines 220a or 220b and does not flow any portion of the fluid through the shaft 210. Even if the rupture disc 202 does not completely block the shaft 210, in the un-ruptured state, a quantity of fluid that flows through the shaft 210 is significantly less (for example, less than 20% in volume) compared to a quantity of fluid that bypasses the shaft 210 and flows through at least one of the turbines 220a or 220b.
When the rupture disc 202 is in a ruptured state, that is, the rupture disc 202 has burst, the burst rupture disc 202 allows a portion of the fluid to bypass the unbalanced sub assembly 200. Specifically, for the illustrated example, the rupture disc allows at least a portion of the flow to bypass the turbine 220a and turbine 220b by allowing fluid to flow through the shaft 210. For example, a quantity of fluid that flows through the shaft 210 after the rupture disc 202 has ruptured is significantly higher than any quantity that flows through the shaft 210 before the rupture disc 202 has ruptured. In other words, although the entirety of the fluid continues to flow through the unbalanced sub assembly 200, only a portion of the fluid flows over the turbines 220a and 220b.
Once the rupture disc is in a ruptured state and a portion of the fluid flow is directed away from either the first turbine 220a, the second turbine 220b or both, the reduced flow over the turbines 220 causes the turbines 220 to reduce a rotational speed. The reduction in rotational speed reduces a vibrational frequency of the induced vibration. While the illustrated implementation shows a bypass passing through the shaft 210, some implementations can use a different flow path, for example, a bypass can be located in an outer housing 204 of the vibration assembly. While the illustrated implementation shows the bypass bypassing both the first turbine 220a and 220b, some implementations can bypass only a single turbine to produce a similar reduction in vibration frequency.
The one or more turbines 220, the shaft 210, and the rupture disc 202 are configured to be drilled out after use. That is, once the casing string 112 is cemented in place, a drill bit is passed through the casing to pulverize the one or more turbines 220, the shaft 210, and the rupture disc 202. To accomplish, this, the aforementioned components can be made of a soft, drillable material, such as an aluminum alloy, a bronze alloy, a brass alloy, a plastic, a composite, or any other drillable material.
The illustrated implementation includes several electronic and electromechanical components as well. A rotational speed sensor 230 is positioned in an outer housing 204 of the vibration assembly 102. The rotational speed sensor is capable of detecting a rotational speed of the turbine 220. If multiple turbines 220 are used, multiple speed sensors 230 can be used. In some implementations, the RPM of the turbine can be used to calculate a flow rate passing through the apparatus 102.
A first hydrostatic pressure sensor 250 is positioned in the outer housing 204 of the vibration assembly 102. The first hydrostatic pressure sensor 250 is capable of measuring a static and/or dynamic pressure within the casing string 112. A second hydrostatic pressure sensor 270 is positioned in the outer housing 204 of the vibration assembly 102. The second hydrostatic pressure sensor 270 is capable of measuring a static and/or dynamic pressure of the annulus 114 between an outer surface of the casing string 112 and an inner surface of the wellbore 106. While only the first pressure sensor 250 and the second pressure sensor 270 are shown in the illustrated implementations, more pressure sensors can be used. For example, a pressure sensor can be used to measure a pressure uphole of the turbine 220a as well as downhole of the turbine 220b in order to measure a pressure drop across the vibration assembly 102. In some implementations, a second RPM sensor can be included to measure the RPMs of the second turbine 220b. Comparing the RPMs of the first turbine 220a and the second turbine 220b can aid in diagnosing turbine blade failures. In some implementations, the vibration assembly 102 can include a temperature sensor 280 capable of measuring a temperature of the annulus 114 between an outer surface of the casing string 112 and an inner surface of the wellbore 106.
The vibration assembly 102 also includes a controller 240 that is positioned in the outer housing 204 of the vibration assembly 102. The controller is capable of receiving, processing, and transmitting data received from the rotational speed sensor 230, the first hydrostatic pressure sensor 250, the second hydrostatic pressure sensor 270, the temperature sensor 290, and any other sensors that are included in the vibration assembly 102. The controller 240 is capable of determining the presence of a casing leak based on a signal from the first hydrostatic pressure sensor 250 and a signal from the second hydrostatic pressure sensor 270. The controller is capable of diagnosing a failure in the rotational speed sensor 230, the first hydrostatic pressure sensor 250, the second hydrostatic pressure sensor 270, or any other sensor included with the vibration assembly 102. The controller can use a telemetry sequence to receive information from the sensors and can determine failures based on the sequence. For example, the controller can send a pre-determined current of voltage to the sensor and measure the sensor response. In some implementations, the controller can send data to a topside facility to be evaluated by a topside controller or a field engineer. The controller is capable of wirelessly transmitting a status of the vibration assembly to a topside facility. For example, the status can include a rotational speed of the vibration inducing device 102, a static pressure within the casing string 112, a static pressure within the annulus 114, or any other status applicable to the operation of the vibration inducing device. In general, all information from the sensors can be transmitted to the topside facility. To accomplish this, the controller can include one or more wireless transmitters and receivers to communicate with the topside facility 108. The one or more wireless transmitters and receivers can transmit and receive information through radio waves, mud pulses, acoustics, Wi-Fi, Bluetooth, or any other wireless transmission technology. In some implementations, the vibration assembly 102 can receive an “on” signal or an “off” signal from a topside facility and respond to the “on” or “off” signal using the same wireless transmission technology.
A battery 260 is positioned in the outer housing 204 of the vibration assembly 102. The battery 260 is capable of imparting electrical energy to the controller 240, rotational speed sensor 230, the first hydrostatic pressure sensor 250, the second hydrostatic pressure sensor 270, and any other electronic component included within the vibration assembly 102. The battery can include a lithium-ion battery, a lead acid battery, a nickel-cadmium battery, or any other type of battery. The battery 260 can be housed within a separate, reinforced chamber to prevent corrosion of the vibration assembly in the event of a battery failure. In some implementations, a generator 206 can be coupled to the turbine 220. In such an instance, the generator 206 can be used to charge the battery.
In the illustrated implementation, the rotational speed sensor 230, the first hydrostatic pressure sensor 250, the second hydrostatic pressure sensor 270, the controller 240, and the battery 260 are all configured to remain within the outer housing 204 of the vibration assembly after the casing string is installed. That is, because these components are located within the housing 204 and out of the flow path, the electronics are not drilled out with the mechanical components. The outer housing is left permanently installed with the casing after cementing operations are completed. The electronics are packaged in such a way to not degrade the casing string after it is permanently installed. For example, the sensors, the battery 260, the controller 240, and any other electronic components are sealed within the housing 204 of the vibration apparatus 102 with no flow-path to either the annulus 114 or the casing string 112.
At 304, a fluid is flowed through the casing string 112. The fluid passes through the vibration inducing device 102. The closed fluid bypass channel is closed to the flow of the fluid through the fluid bypass channel. When in the closed state, the fluid flows entirely through the vibration inducing device 102.
At 306, in response to an increase in a differential pressure of the fluid across the vibration inducing device 102 resulting from an increased flow of the fluid within the casing string 112, the fluid bypass channel is opened. Opening a bypass can include rupturing a rupture disc 202. The rupture disc 202 is configured to rupture when a differential pressure across the vibration induction device goes above a specified threshold. At least a portion of the fluid flows through the opened fluid bypass channel and a remainder of the fluid flows through the vibration inducing device causing a change in the vibration induced within the casing string. At 308, the fluid is flowed through the annulus 114 while the casing string 112 vibrates at the changed vibration induced within the casing string 112. In some implementations, the rupture disc 202 need not be ruptured. That is, the rupture disc 202 is only activated when a need arises. For example, cementing operations can sometimes be performed without needing to open the bypass.
During the installation process, a status of the vibration inducing device 102 is sent wirelessly to a topside facility. In some implementations, the wireless transmission can be transmitted using radio waves. In some implementations, mud pulses, acoustics, Wi-Fi, Bluetooth, or any other wireless transmission technology can be used.
The vibration inducing device 102 is drilled through after setting the casing string at the target depth and after flowing the fluid through the annulus 114, such as cement, and prior to starting production or injection through the casing string 112.
Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims.
This application is a continuation-in-part application of, and claims priority to, U.S. patent application Ser. No. 15/666,711, entitled “Vibration-induced Installation of Wellbore Casing”, to inventors Victor Carlos Costa De Oliveira, Dean S. Porter, and Khaled K. Abouelnaaj, which was filed on Aug. 2, 2017. The disclosure of the foregoing application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15666711 | Aug 2017 | US |
| Child | 15927835 | US |
