Patent Publication Number: US-11643878-B2

Title: Deploying material to limit losses of drilling fluid in a wellbore

Description:
FIELD 
     This specification relates to limiting lost circulation during drilling in subterranean formations. 
     BACKGROUND 
     Lost circulation is a major challenge in drilling operations. When drilling formations with natural or induced fractures, the drilling fluid can flow into these fractures rather than returning up the wellbore, causing a partial or total loss of drilling fluids. Lost circulation represents financial loss due to the non-productive time and extra cost on the drilling fluid to maintain the fluid level in the annulus. In severe lost circulation cases, the flowing of drilling fluid into the loss zone and resulted pressure drop on the open formation compromise the well control and can cause catastrophic results. 
     SUMMARY 
     This specification describes systems and methods to reduce or prevent the loss of drilling fluids into a subterranean formation. These systems and methods use a bottom hole assembly to deploy lost circulation fabric along wellbore walls in loss zones to limit the flow of drilling fluids into a subterranean formation. This approach uses differential pressure around the loss zone to set the lost circulation fabric, reducing the likelihood of formation damage by avoiding the use of additional forces on and interactions with the formation. 
     The lost circulation fabric can be rolled or compressed onto a spool assembly of the bottom hole assembly. This approach enables a short bottom hole assembly to deploy of a large area of fabric to seal a long section of loss zone. During the deployment, differential pressure around the loss zone is utilized to press the lost circulation fabric on the formation. The surface roughness of the lost circulation fabric can be enhanced provides sufficient friction for the lost circulation fabric to grasp on the formation and withstand the differential pressure. This design limits forces on and interactions with the formation applied by the barrier, reducing the possibility of the formation damage. Two types of actuation (ball type and solenoid type) mechanisms are designed to hydraulically drive a lock tube and release all the lock pins simultaneously. This invention represents a new approach of combating the severe lost circulation using lost circulation fabric with a compact bottom hole assembly and a reliable spiral spring release mechanism. 
     In one aspect, bottom hole assemblies with a combined roller-underreamer assembly include: a body configured to be attached to a drill pipe, the body having an uphole end and a downhole end; an uphole ring attached to the body; a downhole ring attached to the body between the uphole ring and the downhole end of the body; a sliding ring mounted around the body between the uphole ring and the downhole ring, the sliding ring attached to the downhole ring by at least one spring; a set tube slidably mounted around the body between the uphole ring and the sliding ring, the set tube having an uphole end and a downhole end; a reamer assembly with at least one first articulated arm with extending between the uphole ring and the downhole end of the set tube; and a roller assembly with: at least one second articulated arm extending between the uphole end of the set tube and the sliding ring; and a roller positioned at a joint of each second articulated arm. 
     In one aspect, bottom hole assemblies with a combined roller-underreamer assembly include: a body configured to be attached to a drill pipe; a first ring attached to the body; a second ring mechanically connected to the body, the second ring spaced apart from the first ring; a set tube slidably mounted around the body between the first ring and the second ring; a reamer assembly with at least one first articulated arm extending between the first ring and the set tube; and a roller assembly with: at least one second articulated arm extending between the set tube and the second ring; and a roller positioned at a joint of each second articulated arm. 
     In some embodiments, the set tube is moveable between a rolling position and a reaming position wherein the reaming position is between the rolling position and the uphole ring. 
     In some embodiments, each roller arm extends radially farther from the body than each reamer arm in the rolling position. 
     In some embodiments, bottom hole assemblies also include an actuator to move the set tube axially along the body. In some cases, the actuator is a mechanical actuator 
     In some embodiments, each reamer arm comprises teeth for removing portions of the wellbore. 
     In some embodiments, the first articulated arms and the second articulated arms are positioned with an angular offset between the first articulated arms and the second articulated arms. In some cases, the reamer assembly has three first articulated arms with a 120 degree angular offset between the first articulated arms and the roller assembly has three second articulated arms with a 120 degree angular offset between the second articulated arms. 
     In some embodiments, bottom hole assemblies also include a third ring attached to the body with the second ring between the third ring and the set tube, the third ring attached to the second ring by at least one spring such that the second ring is slidably mounted around the body. In some cases, the set tube has a first end oriented towards the first ring and a second end oriented towards the second ring and each first articulated arm extends between the first ring and the second end of the set tube. In some cases, each second articulated arm extends between the first end of the set tube and the second ring. 
     In some embodiments, the set tube is moveable between a rolling position and a reaming position wherein the reaming position is between the rolling position and the first ring. In some cases, the roller arm extends radially farther from the body than the reamer arm in the rolling position. In some cases, bottom hole assemblies also include an actuator to move the set tube axially along the body. In some cases, the actuator is a mechanical actuator. In some cases, the reamer arm comprises teeth for removing portions of the wellbore. In some cases, the first articulated arms and the second articulated arms are positioned with an angular offset between the first articulated arms and the second articulated arms. In some cases, the reamer assembly has three first articulated arms with a 120 degree angular offset between the first articulated arms and the roller assembly has three second articulated arms with a 120 degree angular offset between the second articulated arms. 
     These systems and methods are capable of mitigating different degrees of lost circulation (that is, formations with different porosities and permeability) and are effective in handling loss zones with large fracture sizes. These systems and methods deploy lost circulation fabric along walls of a wellbore rather than pumping down fibrous, flaked or granular lost circulation materials (LCM) to seal the fractures in the loss zones. 
     This fabric-based approach can mitigate lost circulation in large-fracture-size loss zones (for example, where typical fracture sizes are greater than 5 millimeters (mm)). In contrast, the size of LCM is limited by the clearance of the bottom hole assembly and the integrity of the downhole tools. By using loss circulation fabric rather fibrous, flaked or granular LCM, the fabric-based approach reduces the likelihood of plugging a downhole bottom hole assembly by eliminating the use of the large-grain LCM used in severe lost circulation situations. 
     Mitigating large-fracture-size loss zones using LCM can require including a PBL sub as part of a bottom hole assembly to divert the LCM loaded fluids into the loss zone. Under extreme severe conditions, deploying LCM can require tripping the drilling bottom hole assembly out the hole, running and setting a drillable plug, applying a cement slurry or expensive thermoset plastic, and drilling-out the plug. The fabric-based approach lowers material costs and reduces non-productive time, which can be a significant operational cost, especially in high value wells such as offshore gas wells. 
     The systems described in this specification are relatively easy to deploy. Structurally, these systems are smaller and simpler than existing mechanical lost circulation mitigation methods that hydraulically or mechanically set expandable tubulars inside a wellbore. These systems include a spiral spring and associated lock pin(s) that act as an easy to deploy anchor for the lost circulation fabric. The spool assembly aligns and deploys the lost circulation fabric to cover an entire inner wall of the formation. In contrast, expandable tubular approaches use a specially designed bottom hole assembly to deploy a section of expandable metallic tubular to isolate the wellbore from the formation across the lost circulation zones. After the deployment, the tubular is permanently set on the formation and cemented with the casing. Using a mechanically or hydraulically driven expansion mechanism on the bottom hole assembly brings a degree of complexity as well as the risk to the operation associated the possibility of a failed expansion. The fabric-based approach avoids these issues as well as the potential drawback that the expandable tubular system adds extra stiffness to the drill pipe due to the tubular and internal expansion system which can be problematic, for example, in high dog-leg severity sections. 
     These systems can include an expandable roller/underreamer assembly that is compact and multifunctional. This approach allows circulation and rotation while running in the hole enabling deploying while drilling without the need for dedicated runs for underreaming and deployment. 
     Lost circulation fabrics include sheets of material whose structure and composition limit the flow of fluids, particularly drilling fluid, through the sheets. Examples of lost circulation fabrics include pliable membranes, meshes, and nets formed from a composite material, such as a fiber-reinforced polymer sheet. The material selected to form the lost circulation fabric includes physical properties selected to withstand downhole environments. The fabric may have a high elastic modulus, high tensile strength, high surface roughness, good toughness, and good thermal stability to withstand harsh downhole environments. Specifically, harsh downhole conditions can refer to high temperatures up to 250 degrees Celsius, high pressures up to 20,000 pounds per square inch (psi), the existence of multiphase media (such as coexisting fluid, gas, and solid media), shock and vibration, confinement, and loss of fluid circulation. To withstand these conditions, the tensile strength of the material of the lost circulation fabric can be between 10 and 10,000 megapascals (MPa), the toughness can be between 1 and 100 kilojoules per square meter (kJ/m 2 ), and the thermal stability can be greater than or equal to 100 degrees Celsius. Polymers, such as nylon, polycarbonate, polypropylene, and high-temperature polyethylene may be used to form a lost circulation fabric. High-temperature may refer to an ability of the material to retain its thermal stability in temperature ranges greater than the typical temperature range of commercially available types. For example, these polymers may be used to form a fiber-reinforced polymer used to make the lost circulation fabric. In other implementations, composites, such as carbon-reinforced polymers and glass fiber-reinforced polymers may be used to form lost circulation fabrics. In some cases, lost circulation fabrics are textiles made by weaving, knitting, or felting natural or synthetic fibers. In some cases, lost circulation fabrics are membranes, for example, extruded polymer sheets. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic of a drilling system that includes a rig and a drill string supported by the rig. 
         FIG.  2    is a side view of the bottom hole assembly of  FIG.  1   . 
         FIGS.  3 A and  3 B  are, respectively, a side view and a cross-sectional view of a spool ring mounted on a body of the bottom hole assembly. 
         FIG.  4    is a cross-sectional view of a spring ring. 
         FIGS.  5 A and  5 B  are, respectively, a side view and a top view of the spool ring mounted on the body, the relaxed spring ring, and the lost circulation fabric deployed covering walls of the wellbore. 
         FIG.  6 A- 6 C  are cross-sectional views showing a spring release for mechanically releasing a spring ring. 
         FIGS.  7 A and  7 B  are, respectively, a side view and a schematic top view of a combined roller-underreamer assembly in the rolling position. 
         FIGS.  8 A and  8 B  are, respectively, a side view and a schematic top view of a combined roller-underreamer assembly in the reaming position. 
         FIGS.  9 A- 9 J  illustrate a positioning system that controls the position of the set tube relative to the body of the bottom hole assembly.  FIGS.  9 A,  9 C,  9 E,  9 G and  9 I  are partial cross-sectional views of the positioning system and  FIGS.  9 B,  9 D,  9 F,  9 H , and  9 J are schematics show the position of a cam along a guide path during operation of the positioning system. 
         FIG.  10 A  is a schematic of a linear version of a guide path  284  and  FIG.  10 B  shows the guide track as arranged on the body of a bottom hole assembly. 
         FIGS.  11 A- 18 C  illustrate operation of the bottom hole assembly.  FIGS.  11 A,  12 A,  13 A,  14 A,  15 A,  16 A,  17 A, and  18 A  are schematic side views of a bottom hole assembly in a wellbore.  FIGS.  11 B,  12 B,  13 B,  14 B,  15 B,  16 B,  17 B, and  18 B  are perspective views of the bottom hole assembly in the wellbore.  FIGS.  11 C,  12 C,  13 C,  14 C,  15 C,  16 C,  17 C, and  18 C  are schematic plan views of the spool ring  140  of the bottom hole assembly.  FIGS.  11 D,  12 D,  13 D,  14 D,  15 D,  16 D, and  17 D  are schematic plan views of the combined roller-underreamer assembly of the bottom hole assembly. 
         FIG.  19    is a flowchart of a method  400  for deploying the lost circulation fabric  148  in a wellbore  106 . The method  400  is described with reference to  FIGS.  11 A- 18 C . 
         FIGS.  20 A and  20 B  are cross-sectional side views of a spring release mechanism. 
         FIGS.  21 A and  21 B  are partial cross-sectional views of a positioning mechanism. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     This specification describes a bottom hole assembly for deploying a lost circulation fabric in a wellbore to reduce or prevent lost circulation. The lost circulation fabric can be a high strength membrane or mesh that is deployed to cover portions of a loss zone in a wellbore that experience lost circulation due to, for example, highly fractured formations. The lost circulation fabric prevents drilling fluid from escaping into the formation from the wellbore by acting as a barrier (for example, an impermeable membrane) between the wellbore and the formation. The bottom hole assembly includes a spring ring, a spool ring, and a underreamer to transport, deploy, and press the lost circulation fabric to walls of the wellbore. Deploying the lost circulation fabric in the wellbore at large loss zone of the formation reduces lost circulation fluid while also reducing the risk of formation damage. 
       FIG.  1    shows a view of a drilling system  100  that includes a rig  102  and a drill string  104  supported by the rig  102 . The drill string  104  extending into a subterranean formation  108  is being used to form a wellbore  106 . A fluid pump  110  pumps drilling fluid to the drill string  104  via a drill fluid line  112 . The drilling fluid flows downhole, though the drill string  104 , and out an outlet  113  of a drill bit  114  that is part of a bottom hole assembly  116 . Drilling fluid exiting the outlet  113  mixes with cuttings detached from the formation  108  by the drill bit  114 . The drilling fluid carries cuttings uphole towards the surface  120  through an annular space  118  between the drill string  104  and the walls of the wellbore  106 . The drilling fluid and cuttings flow out of the formation  108 , though a fluid line  130 , and into a container  132  for treatment, or transportation to a treatment facility. 
     The drill string  104  includes a drill pipe  103  supporting the bottom hole assembly  116  which includes the drill bit  114 . The bottom hole assembly  116  includes a body  134  with an uphole attachment end  136  opposite the drill bit  114 . In the drilling system  100 , the uphole attachment end  136  of the bottom hole assembly  116  is attached to the drill pipe  103  of the drill string  104 . The uphole attachment end  136  has threaded portions that engage with complimentary threads on the drill pipe  103 . In some systems, the attachment ends use a locking bar, magnets, bolts, tongue and groove assemblies, or any combination thereof, to attach the ends of the body to the drill pipe and drill bit  114 . 
       FIG.  2    shows a side view of the bottom hole assembly  116 . The bottom hole assembly  116  includes a spool ring  140 , a spring ring  142 , and a combined roller-underreamer assembly  144 , each attached to the body  134 . The spool ring  140  has a plurality of spools  146  on which a rolled, compressed, or coiled lost circulation fabric  148  is releasably mounted.  FIG.  2    shows the lost circulation fabric  148  in an initial, or undeployed, position. Each roll of lost circulation fabric  148  is mounted on one of the plurality of spools  146  and attached to the spring ring  124  at a first end  150  of the lost circulation fabric  148 . 
     The spring ring  142  is disposed around the body  134 , downhole of the spool ring  140 . The spring ring  142  is shown in a compressed position, attached to the body  134 . When released, the spring ring  142  expands radially outward from the body  134 . The structure and operation of the spool ring  140  and the spring ring  142  are described in more detail with reference to  FIGS.  3 A- 5 B . 
     The combined roller-underreamer assembly  144  is attached to the body  134 , downhole of both the spool ring  140  and the spring ring  142 . When used to describe the relative positions of components of the bottom hole assembly on the body  134 , the term “uphole” is used to indicate closer to the uphole attachment end and “downhole” is used to indicate closer to the end of the body where the drill bit  114  is attached. These terms indicate position of components on the body/bottom hole assembly whether the bottom hole assembly is in a wellbore or at the surface. 
     The combined roller-underreamer assembly  144  includes an uphole attachment point  164  and a downhole attachment point  176  spaced apart from the uphole attachment point  164 . In the illustrated system, the uphole attachment point  164  is a hinge mounted on a first ring  165  attached to and fixed in position relative to the body  134  and the downhole attachment point  176  is a hinge mounted on a second ring  177  attached to and fixed in position relative to the body  134 . Some systems use other mechanisms for the attachment points. 
     The combined roller-underreamer assembly  144  also includes a set tube  152 , a reamer assembly  145 , and a roller assembly  147 . The set tube  152  is slidably mounted around the body  134  between the first ring  165  and the second ring  177 . The reamer assembly  145  includes at least one first articulated arm (that is, a reamer arm  154 ) extending between the first ring  165  and the set tube  152 . Similarly, the roller assembly  147  includes at least one second articulated arm (that is, a roller arm  156 ) extending between the set tube  152  and the second ring  177 . The roller assembly  147  also includes a roller  178  positioned at a joint of each roller arm  156 . The reamer arm  154  bends at a central hinge  158 . The roller arm  156  also bends at a central hinge  160 . 
     The set tube  152  is moveable between a rolling position and a reaming position wherein the reaming position is between the rolling position and the first ring  165 . When the set tube  152  is in the rolling position, the central hinge  160  of the roller arm  156  extends radially farther from the body  134  than the central hinge  158  of the reamer arm  154 . When the set tube  152  is in the reaming position, the central hinge  158  of the reamer arm  154  extends radially farther from the body  134  than the central hinge  160  of the roller arm  156 . The structure and operation of the combined roller-underreamer assembly  144  is described in more detail with reference to  FIGS.  7 A- 8 B . 
       FIG.  3 A  is a side view of the spool ring  140 , the spring ring  142 , and lost circulation fabric  148  mounted on the spools  146  before deployment.  FIG.  3 B  is a cross section of the spool ring  140  mounted on the body  134 , and the lost circulation fabric  148  mounted on the spools  146 . In the bottom hole assembly  116 , the spool ring  140  is disposed an outer surface of the body  134 . 
     The spool ring  140  includes a base  182  and arms  184  extending radially outward from the base  182 . The base  182  is mounted on the body  134  with the arms  184  holding the spools  146  away from the base  182  so the spools  146  can rotate during deployment of the lost circulation fabric  148 . Some spool rings do not have a base. In these spool rings, the arms  184  are directly attached to extend outward from the body  134  rather than having a base interposed between the arms  184  and the body  134 . 
     The spools  146  includes a first set of spools  146  and a second set of spools  146  offset from the first set of spools  146  towards a downhole end of the body  134 . The second set of spools  146  is positioned with an angular offset from the first set of spools  146  such that rolls of the lost circulation fabric  148  mounted on the first set of spools  146  overlap rolls of the lost circulation fabric  148  mounted on the second set of spools  146 . The spool ring  140  has six spools  146  in each set of spools  146 . Some spool rings have fewer or more spools  146  in each set. 
     In  FIGS.  3 A and  3 B , the spring ring  142  is in its compressed position and has a compressed inner diameter D CI  and a compressed outer diameter D CO . The compressed inner diameter D CI  is defined by an inner surface  190  of the spring ring  142 . The compressed outer diameter is defined by an outer surface  192  of the spring ring. The compressed inner diameter D CI  is equal to or slightly larger than an outer diameter D B  of the body  134 , defined by an outer surface  194  of the body  134 . The inner surface  190  of the spring ring  142  abuts the outer surface  194  of the body  134  in the compressed position. 
       FIG.  4    is a cross-sectional view of the spring ring  142 . The spring ring  142  is a coiled spring that expands radially outward from the body  134  towards the walls of the wellbore  106  when the spring ring  142  is released. The spring ring  142  is held in its compressed position by a locking pin  196  with an engagement surface  198  at a first end  200 . A second end  202  of the locking pin  196  is attached to the outer surface  192  of the spring ring  142 . A locking member  204  with a complimentary locking surface  206  is arranged within the body  134 . The engagement surface  198  of the locking pin  196  engages the complimentary locking surface  206  of the locking member  204  to hold the locking pin  196  with the locking member  204 . Axial movement of the locking member  204  disengages the engagement surface  198  of the locking pin  196  from the complimentary locking surface  206  of the locking member  204 . This disengagement releases the spring ring  142  from its compressed position. With no force holding the spring ring  142  in its compressed position, the spring ring  142  expands radially outward from the body  134 . 
       FIG.  5 A  is a side view of the spool ring  140 , the relaxed spring ring  142 , and deployed lost circulation fabric  148 .  FIG.  5 B  is a top view of the spool ring  140  mounted on the body  134 , the relaxed spring ring  142 , and the lost circulation fabric  148  deployed covering walls of the wellbore  106 . The lost circulation fabric  148  has been released from the spools  146  to attach to walls of the wellbore  106 , however, the first end  150  of the lost circulation fabric  148  remains attached to the spring ring  142 . The spring ring  142  is in the relaxed position and has a relaxed inner diameter D RI  and a relaxed outer diameter D RO , defined by the inner surface  190  of the spring ring  142  and the outer surface  192  of the spring ring  142 , respectively. In the relaxed position, the inner surface  190  of the spring ring  142  is spaced apart from the outer surface  194  of the body  134  and at least part of the outer surface  192  of the spring ring  142  abuts the walls of the wellbore  106 . 
       FIG.  6 A- 6 C  are cross-sectional views showing a spring release  210  for mechanically releasing the spring ring  142 . The spring release  210  includes an internal compartment  212  defined by sidewalls  214 ,  215 ,  217  of the body  134  and the locking member  204  slidably disposed in the internal compartment  212 . The locking member  204  can move axially in the internal compartment  212  from an initial position engaging the lock pin  196  to an actuated position disengaged from the lock pin  196  in. A shearing pin  219  holds the locking tube in the initial position. A vent block  216  defines an opening  218  fluidly connecting the internal compartment  212  to an interior cavity  220  of the body  134 . Air flows through the opening  218  when the locking member  204  moves axially within the internal compartment  212  to equalize the pressure between the internal compartment  212  and the interior cavity  220  of the body  134 . 
     The body  134  has a recess  222  on the sidewall  214  facing the interior cavity  220  of the body  134 . A control member (for example, control tube  224 ) is slidably mounted to the recess  222 . A shearing pin  226  attached to the control tube  224  and the sidewall  214  constrains the control tube  224  in an initial axial position in the recess  222 , as shown in  FIG.  6 A . In the initial position the control tube  224  covers a channel  228  (fluid port) that fluidly connects the internal compartment  212  to the recess  222  and the interior cavity  220  of the body  134 . The recess  222  has a notch  230  arranged at a downhole end  232  that extends farther into the sidewall  214  of the body  134  relative to the recess  222 . 
     An actuator  234  is fixed to the control tube  224  at an uphole end  236 . The actuator  234  has a stem  238  and a finger  240  that protrudes radially into the interior cavity  220  of the body  134 . The finger  240  attaches to the stem  238  at a downhole end  242  of the actuator  234 . Together the stem  238  and the finger  240  form an “L” shape. Some actuation members are collet fingers. 
     To release the spring ring  142  from the compressed position to the relaxed position, the actuator  234  is engaged. For example, a ball  244  can be used to operate the actuator  234 . The ball  244  is inserted into the drilling fluid line  112  so that the ball  244  flows through the drill pipe  103  into the body  134  and out the drill bit  114 . In some actuation mechanisms, multiple balls are inserted into the drill fluid line  112 . 
     In the initial (compressed) position, the spring release  210  is as shown in  FIG.  6 A . The spring ring  142  is axially and rotatably constrained to the body  134  of the bottom hole assembly  116  in the compressed position. To release the spring ring  142 , the ball  244  is inserted into the drilling fluid line  112  and moves downhole with the flow of drilling fluid. The ball moves through the drill string  104  and into the interior cavity  220  of the body  134 . The interior cavity  220  of the body  134  is fluidly connected to an interior of the drill pipe  103  that defines the fluid path of the drilling fluid. The ball  244  engages with the finger  240  of the actuator  234  and translates the actuator  234  and the control tube  224  axially on the sidewall  214 . The force of the ball  244  moving downhole breaks the shearing pin  226 , moving the control tube  224  and actuator  234  from the initial position to an intermediate position. 
     The intermediate position is shown in  FIG.  6 B . In the intermediate position of the spring release  210 , the channel  228  is exposed, fluidly connecting the interior cavity  220  of the body  134  with the internal compartment  212 . Drilling fluid flows through the channel  228 , into the internal compartment  212 , and applies a force to an uphole section  246  of the locking member  204 . The pressure increases and applies sufficient force to overcome the static frictional force between the locking tube and the sidewalls  214 ,  215  of the internal compartment  212 . Typically, a momentary decrease of the flow rate is observed when the control ball blocks the flow path on the control tube before it slides down and releases the ball. The locking member  204  moves axially within the internal compartment  212  and disengages the lock pins  196 . Air or fluid is pressed out of the internal compartment  212  by the movement of the locking member  204 , through the opening  218  of the vent block  216 . In this configuration, the spring ring  142  is released and begins to expand radially, as shown in  FIG.  6 B . 
     The relaxed position of the spring release  210  is shown in  FIG.  6 C . The spring ring  142  abuts the walls of the wellbore  106  while still permanently attached to the first end  150  of the lost circulation fabric  148 . The locking member  204  abuts the vent block  216  and remains static. The control tube  224  and actuator  234  continue to move axially with the ball  244  until the finger  240  aligns with the notch  230  of the recess  222 . The actuator  234  is made of a resilient material. When the actuation member aligned with the notch  230 , the force of the ball  244  presses the finger  240 , and part of the stem  238 , into the notch  230 . The actuator  234  resiliently bends to disengage from the ball  244 . The ball  244  then continues to flow with the drilling fluid, exits the drill bit  114 , and returns to the surface with the drilling fluid. In some spring release mechanism, the actuation member is made of a metal or plastic that permanently deforms in the relaxed position of the spring release mechanism. 
       FIGS.  7 A and  7 B  shows the combined roller-underreamer assembly  144  in the rolling position.  FIGS.  8 A and  8 B  show the combined roller-underreamer assembly  144  in the reaming position. As described with respect to  FIG.  2   , the set tube  152  is moveable between a rolling position and a reaming position wherein the reaming position is between the rolling position and the first ring  165 . When the set tube  152  is in the rolling position, the central hinge  160  of the roller arm  156  extends radially farther from the body  134  than the central hinge  158  of the reamer arm  154 . When the set tube  152  is in the reaming position, the central hinge  158  of the reamer arm  154  extends radially farther from the body  134  than the central hinge  160  of the roller arm  156 . 
     The second ring  177  include an uphole portion  252  attached to a downhole portion  254  by springs  256 . The hinge  176  is attached to the uphole portion  252  of the second ring  177  that is mounted to the body  134 . The uphole portion  252  of the second ring  177  is axially movable relative to the downhole portion  254  of the second ring  177 . The downhole portion  254  of the second ring  177  fixes the position the second ring relative to the body  134  of the bottom hole assembly. The springs  256  compensate to some extent for variations the dimensions of the wellbore when the combined roller-underreamer assembly  144  is in rolling position. For example, movement of the combined roller-underreamer assembly  144  through a narrower portion of a wellbore will push the rollers  178  radially inward and compress the springs  256  by pushing the uphole portion  252  of the second ring  177  towards the downhole portion  254  of the second ring  177 . When the wellbore widens, the springs  256  bias the uphole portion  252  of the second ring  177  away the downhole portion  254  of the second ring  177  helping move the rollers  178  radially outward to help maintain contact with walls of the wellbore. The first ring  165  is arranged uphole of the set tube  152 . The uphole portion  252  of the second ring  177  is arranged downhole of the set tube  152 . 
       FIGS.  9 A,  9 C,  9 E,  9 G and  9 I  are partial cross-sectional views of a positioning system  260  that controls the position of the set tube  152  relative to the body  134 . The positioning system includes a cam  282  engaged with a guide path  284 .  FIGS.  9 B,  9 D,  9 F,  9 H, and  9 J  show the position of the cam  282  along the guide path  284  during operation of the positioning system  260 . The positioning system  260  and the spring release mechanism are controlled by balls with different diameters. The mechanism controlled by small balls is located in the lower part of the bottom hole assembly so that small balls do not activate the upper mechanism, and larger balls which control the upper mechanism get caught by a collection basket before they reach the lower mechanism. 
     The positioning system  260  includes a control element (for example control tube  286 ). Movement of the control tube  286  relative to the body  134  controls the position of the set tube  152  relative to the body  134 . In the positioning system  260 , the cam  282  projects radially outward from the control tube and the guide path  284  is a groove defined in a surface of a sidewall  264  of the body  134 . In some positioning systems, the guide path is defined in an outer surface of the control tube and the cam projects radially inward from the sidewall  264 . 
     A finger  288  is attached to a downhole end of the control tube  286  extending radially into the interior cavity  220  of the body  134 . In the positioning system  260 , the finger  288  and control tube  286  are separate components. In some positioning mechanism, the finger and the tube element are formed as a single component. The control tube  286  and the finger  288  are attached such movement of the finger  288  also moves the control tube  286 . Due to the interaction between the cam  282  and the guide path  284 , axial movement of the finger  288  and the control tube  286  rotates the control tube. 
     The positioning system  260  includes a first interior chamber  262  defined by sidewalls  264 ,  266 ,  268  of the body  134 . An uphole end  270  of the set tube  152  extends into the first interior chamber  262 . The sidewalls  264 ,  266 ,  268  of the body  134  and the uphole end  270  of the set tube  152  define a pressure chamber  272 . The pressure chamber  272  fluctuates in volume as the set tube  152  moves axially between the reaming position and the rolling position. 
     The sidewall  264  defines a recess  274  that includes a first notch  278  and a second notch  280  on a surface of the sidewall  264  facing the interior cavity  220 . A first spring  290  is arranged in the first notch  278  between the control tube  286  and the sidewall  264 . The first spring  290  biases the control tube  286  towards an uphole end of bottom hole assembly. In the absence of other forces, the first spring  290  pushes the control tube  286  to abut an uphole boundary  292  of the recess  274 , as shown in  FIG.  9 A . In this configuration, a fluid port  294  (channel) is covered. When exposed, the fluid port  294  connects the first interior chamber  262  of the positioning system  260  to the interior cavity  220  of the body  134 , as described in more detail with reference to  FIGS.  9 C,  9 E, and  9 G . 
     A second interior chamber  296  is defined by sidewalls  298 ,  300  of the body  134  and a chamber-isolating ring  302 . A downhole end  304  of the set tube  152  extends into the second interior chamber  296 . A second spring  308  is arranged in the second interior chamber  296  and biases the set tube in the reaming position (shown in  FIGS.  9 A and  9 I ). 
     As the set tube  152  moves its reaming position to its rolling position, the volume of the pressure chamber  272  increases and the volume of the second interior chamber  296  decreases. As the set tube  152  moves from its rolling position to its reaming position, the volume of the pressure chamber  272  decreases and the volume of the second interior chamber  296  increases. The uphole end  270  of the set tube  152  has a first equalizing port  310  that fluidly connects the pressure chamber  272  with the annular space between the body  134  and the wellbore  106 . The first equalizing port  310  allows fluid to gradually escape the pressure chamber  272 . The chamber-isolating ring  302  has a second equalizing port  312  that fluidly connects the second interior chamber  296  with the annular space between the body  134  and the wellbore  106 . The second equalizing port  312  allows pressure in the second interior chamber  296  to match pressure in the annulus between bottom hole assembly and walls of the wellbore. 
       FIGS.  9 B,  9 D,  9 F,  9 H, and  9 J  show the cam  282  engaged with the guide path  284  in various positions. The guide path  284  includes a pattern  285  that has a series of five positions: position A, position B (second position), position C (third position), position D (fourth position), and position E (fifth position). Position A and Position E are closed positions (that is, the control tube blocks inlet port). Position B and Position D are release positions (that is, the finger attached to control flexes to release an actuator ball). Position C is an open position (that is, the control tube is not blocking the inlet port). The guide path  284  is a continuous path that extends around the inner wall of the body  134  or the outer wall of control tube. The term “continuous” is used to indicate a path that moving forward along the path from an initial point returns to the initial point. Position E of one pattern is Position A of the next pattern. 
       FIG.  10 A  is a schematic of a linear version of the guide path  284 .  FIG.  10 B  shows the guide track  284  as arranged on the body  134 . The pattern  285  repeats around the circumference of the body  134  so that the cam  282  seamlessly transitions from one pattern to the next. For example, position A and position A′ are the same position on different patterns, and position E connects directly to position A′ to connect the two different patterns. The pattern  285  may repeat a number of times, such that the guide track has an A/B/C/D/E pattern, an A′/B′/C′/D′/E′ pattern, and an A″/B″/C″/D″/E″ pattern. In such a configuration, the E″ position would connect back to the A position to complete the guide path  284 . 
       FIG.  9 B  shows the guide path  284  engaged with the cam  282  at the initial first position (position A).  FIG.  9 D  shows the guide path  284  engaged with the cam  282  at the second position (position B).  FIG.  9 F  shows the guide path  284  engaged with the cam  282  at the fourth position (position D).  FIG.  9 H  shows the guide path  284  engaged with the cam  282  at the fifth position (position E).  FIG.  9 J  shows the guide path  284  engaged with the cam  282  at a repeated first position (position A′). The guide path  284  and cam  282  control the position of the combined roller-underreamer assembly  144 . Position A of the cam  282  corresponds with the reaming position of the combined roller-underreamer assembly  144 . Position D of the cam  282  corresponds with the rolling position of the combined roller-underreamer assembly  144 . As the cam  282  moves through a diagonal portion of the guide path, for example A to B or C to D, the cam also rotates relative to the body  134 , control tube  286 , and finger  288 . 
     To move the combined roller-underreamer assembly  144  from the rolling position to the reaming position, an actuator, for example, a ball engages the finger  288  and moves it downhole. As described with reference to  FIGS.  6 A- 6 C , a first ball  314  is inserted into the drill string  104  at the surface. Drilling fluid and gravity carry the first ball  314  through the drill string  104  and into the body  134  of the bottom hole assembly  116 , as shown in  FIG.  9 A . The first ball  314  then engages with the finger  288  and pulls the finger  288 , control tube  286 , and cam  282  axially downhole with the flow of the drilling fluid against the biasing force of the first spring  290 . As the control tube  286  moves away from the uphole boundary  292  of the recess  274 , the fluid port  294  is exposed to the drilling fluid in the interior cavity  220  of the body  134 . 
     In  FIG.  9 C , the finger  288  is received by the second notch  280 , and flexes into the notch releasing the first ball  314 . At this point, the first spring  290  is fully compressed, the cam  282  is in position B, and drilling fluid enters the first interior chamber  262  via the fluid port  294 . The drilling fluid in the first interior chamber  262  applies a force to the uphole end  270  of the set tube  152  and begins to apply enough pressure to move the set tube  152  downhole against the biasing force of the second spring  308 .  FIG.  9 C  illustrates a transitional position between the rolling position and the reaming position. The set tube  152  is equidistant between the first ring  165  and the uphole portion  252  of the second ring  177 . 
     Once the first ball  314  is released when the cam  282  is in position B, the first spring  290  presses the control tube  286  uphole moving the cam  282  from position B, through position C and into position D. In position D, the guide path prevents the cam  282  and the control tube  286  from continuing to move uphole. When the cam  282  is in position D, the control tube  286  does not cover the fluid port  294 . The finger  288  relaxes back to its initial configuration, in which a ball could engage the finger  288 . Additional fluid continues to flow through the fluid port  294  and presses the set tube  1523  downhole, until the movable member hits a stop surface  316  of the body  134 . At this point, the second spring  308  is fully compressed and the combined roller-underreamer assembly  144  is in the rolling position. The combined roller-underreamer assembly  144  maintains this position due to exposure of the uphole end of the set tube  152  to pressure of drilling fluid inside the drill string. 
     The combined roller-underreamer assembly  144  remains at this position until the reaming position is desired. To return to the reaming position, a second mechanical actuator, for example a second ball  318 , is loaded into the drill string  104 . The cam  282 , in position D, is free to move axially downhole provided a sufficient force overcomes the biasing force of the first spring  290 . Like first ball  314 , the second ball  318  flows through the drill string to engage the finger  288 , as shown in  FIG.  9 G . The cam  282 , finger  288 , and control tube  286  move axially downhole, against the bias of the first spring  290  until the finger  288  flexes and disengages the ball  318 . At this point the cam  282  is at position E. When the ball is released, the first spring  290  moves the cam  282 , the finger  288 , and the control tube  286  uphole. The cam  282  moves from position E to position A′ and the tube element returns to abut the uphole boundary  292  of the recess  274 , as shown in  FIG.  9 I . 
     The return of the control tube  286  to its initial position covers the fluid port  294  and removes fluid connection between the interior of the body  134  and the first interior chamber  262 . The fluid in the interior chamber at least partially drains out of the first equalizing port  310  thereby removing the compressive force on the second spring  308 . The second spring moves the set tube  152  uphole into the reaming position. The combined roller-underreamer assembly  144  will remain in the reaming position until the fluid port  294  is reopened by a third actuator. 
       FIGS.  11 A- 18 C  illustrate operation of the bottom hole assembly  116 .  FIGS.  11 A,  12 A,  13 A,  14 A,  15 A,  16 A,  17 A, and  18 A  are schematic side views of the bottom hole assembly  116  in the wellbore  106 .  FIGS.  11 B,  12 B,  13 B,  14 B,  15 B,  16 B,  17 B, and  18 B  are perspective views of the bottom hole assembly  116  in the wellbore  106 .  FIGS.  11 C,  12 C,  13 C,  14 C,  15 C,  16 C,  17 C, and  18 C  are schematic plan views of the spool ring  140  of the bottom hole assembly  116  in the wellbore  106 .  FIGS.  11 D,  12 D,  13 D,  14 D,  15 D,  16 D, and  17 D  are schematic plan views of the combined roller-underreamer assembly  144  of the bottom hole assembly  116  in the wellbore  106 .  FIG.  19    is a flowchart of a method  400  for deploying the lost circulation fabric  148  in a wellbore  106 . The method  400  is described with reference to  FIGS.  11 A- 18 C . 
     In  FIGS.  11 A- 11 D , the bottom hole assembly  116  translates by the drill string  104  to a lost circulation area  330  of the wellbore  106  (step  402 ). At the lost circulation area  330 , drilling fluid exits the wellbore  106  and cannot be retrieved for later processing and manufacturing. Once the lost circulation area  330  is located, the bottom hole assembly positioned with the combined roller-underreamer assembly  144  is slightly downhole of the lost circulation area  330 , for example about 10 ft. to about 100 ft. During translation of the bottom hole assembly  116 , the combined roller-underreamer assembly  144  is in the rolling position. When aligned slightly below the downhole assembly, the positioning system  260  is activated to move the combined roller-underreamer assembly  144  from the rolling position to the reaming position, as shown in  FIGS.  12 A- 12 D . Once secured in the reaming position, the drill string  104  rotates. The body  134  of the bottom hole assembly  116  and all attached components (the spool ring  140 , the spring ring  142 , and the combined roller-underreamer assembly  144 ) rotate with the drill string  104 . The teeth  169  on the reamer arms  154  loosen and cut the formation  108  during rotation. The reamer arms  154  engage the walls of the wellbore  106  and enlarge the cross section of the wellbore  106 . The drill string  104  moves axially downhole or uphole to enlarge a section  332  (reamed section) of the wellbore  106  (step  404 ). The reamed section  332  has a diameter D UR . The portion of the wellbore  106  that aligns with the spool ring  140  has a diameter D SR . The diameter D UR  is larger than the diameter D SR . 
     In  FIGS.  13 A- 13 D , the positioning system  260  is actuated a second time and the combined roller-underreamer assembly  144  moves from the reaming position to the rolling position. The drill string  104 , with the bottom hole assembly  116 , moves axially downhole to align the spring ring  142  with the reamed section  332  (Step  406 ). The spring release  210  is actuated to move the locking member  204  and release the locking pin  196 . The spring ring  142  moves from its compressed position to its relaxed position and abuts the reamed section  332  of the wellbore  106  (step  408 ), as shown in  FIGS.  14 A- 14 D . In this configuration, the lost circulation fabric  148  extends from the reamed section  332  of the wellbore  106  to the drill string  104  across the flow of drilling fluid up the annulus between the drill string and walls of the wellbore. 
       FIGS.  15 A- 15 D  show the lost circulation fabric  148  being deployed with the uphole flow of the drilling fluid begins to pull the lost circulation fabric off the spools. The first end  150  of the lost circulation fabric  148  remains attached to the spring ring  142 . The drilling fluid balloons a middle section  336  of the lost circulation fabric uphole, in the direction of the drilling fluid flow. The spools  146  rotate to release the lost circulation fabric  148  as the middle section  336  extends uphole. Eventually a second end  338  of the lost circulation fabric releases from the spool  146  and flows uphole. The uphole flow of the drilling fluid presses the lost circulation fabric  148  against the walls of the wellbore  106 , covering the lost circulation area  330 , as shown in  FIGS.  16 A- 16 D . In addition, the differential pressure between the lost circulation area  330  and the wellbore  106  helps adhere the lost circulation fabric  148  to the wall of the wellbore  106 . As previously discussed, the first and second sets  186 ,  188  of the spools  146  on the spring ring  142  overlap so that the entire circumference of the wellbore wall is covered in lost circulation fabric  148 , as shown in  FIGS.  16 B,  17 B, and  18 B . 
     In  FIGS.  17 A- 17 D , the lost circulation fabric  148  is deployed. To further adhere the lost circulation fabric  148  to the wellbore  106 , the drill string  104  is translated uphole so that the rollers  178  of the combined roller-underreamer assembly  144  abut the walls of the wellbore  106  and press the lost circulation fabric  148  to the walls of the wellbore  106  (step  410 ). The drilling system  100  may then resume drilling (step  412 ) or the bottom hole assembly  116  may be completely removed (step  414 ). The lost circulation fabric  148  and the spring ring  142  remain in the wellbore  106  during and after drilling. When drilling has completed, the drill string  104  is completely removed from the wellbore  106 . 
       FIGS.  20 A and  20 B  are cross-sectional side views of a spring release mechanism  340  that is substantially similar to the spring release  210 . However, the spring release mechanism  340  is electronically rather than mechanically actuated. The spring release mechanism  340  includes the internal compartment  212  and the locking member  204  arranged in the internal compartment  212 . The locking member  204  engages with the pins  196  of the spring ring  142  in the compressed position ( FIG.  20 A ). The spring release mechanism  340  further includes a recess  342  arranged in the sidewall  215  of the body  134 . A power module  348  and a control module  350  are disposed in the recess  342 . A channel  228  connects the recess  342  to the internal compartment  212 . The recess  342  is arranged on an exterior surface of the sidewall  215 , uphole relative to the internal compartment  212 . A solenoid actuator  344  disposed in the recess  342  includes an arm  346  that extends into the internal compartment  212  through the channel  228 . The arm  346  abuts the locking member  204 . In some spring release mechanisms, the arm is attached to the lock tube. The solenoid actuator  344  has a retracted state and an extended state. The retracted state is shown in  FIG.  20 A  and the extended state is shown in  FIG.  20 B . Moving from the retracted state to the extended state translates or extends the arm  346  axially in the downhole direction. In some spring release mechanisms, the solenoid actuator also moves from the extended state to the retracted state. Moving from the retracted state to the extended state translates or retracts the arm axially in the uphole direction. 
     The spring release mechanism further includes a cover  352  that extends on the exterior wall of the body  134  to cover the recess  342 . The cover  352  fluid seals the recess  342  so that the electronics (power module  348 , control module  350 , and solenoid actuator  344 ) remain dry during operation. Seals  524  sealably connect the arm  346  to the channel  228 . 
     To actuate the spring release mechanism  340 , the control module  350  receives a signal to change the state of the spring ring  142 . The control module  350  then signals to the solenoid actuator to change state from the retracted position to the extended position. Moving the arm  346  axially downhole presses the locking member  204  downhole and disengages the locking member  204  from the locking pin  196 . The spring ring  142  then relaxes and expands radially until the spring ring  142  abuts the wellbore  106 . 
       FIGS.  21 A and  21 B  are partial cross-sectional views of a positioning mechanism  370 . The positioning mechanism  370  is substantially similar to the positioning system  260 . However, the positioning mechanism  370  is electronically rather than mechanically actuated. The positioning mechanism includes the first interior chamber  262  and the second interior chamber  296  defined in the body  134 . The uphole end  270  of the set tube  152  is arranged in the first interior chamber  262  and the downhole end  304  of the set tube  152  is arranged in the second interior chamber  296 . 
     The positioning mechanism  370  further includes a recess  372  arranged in an exterior wall  273  of the body  134 . A power module  374  and a control module  376  are disposed in the recess  342 . A channel  378  connects the recess  342  to the first interior chamber. The recess  342  is arranged on an exterior sidewall of the body  134  above the first interior chamber  262 . A solenoid actuator  380  disposed in the recess  342  includes an arm  382  that extends into the first interior chamber  262  through the channel  228 . The arm  382  attaches to the uphole end of  290  of the set tube  152 . The solenoid actuator  380  has a retracted state and an extended state. The retracted state is shown in  FIG.  21 A  and the extended state is shown in  FIG.  21 B . Moving from the retracted state to the extended state, translates or extends the arm  382  axially in the downhole direction. The solenoid actuator  380  also moves from the extended state to the retracted state. Moving from the retracted state to the extended state, translates or retracts the arm  382  axially in the uphole direction. 
     The positioning mechanism  370  further includes a cover  384  that extends on the exterior wall  273  of the body  134  to cover the recess  372 . The cover  384  fluid seals the recess  372  so that the electronics (power module  374 , control module  376 , solenoid actuator  380 ) remain dry during operation. Seals  386  sealably connect the arm  382  to the channel  378 . 
     To actuate the positioning mechanism  370 , the control module  376  receives a signal to change the state of the combined roller-underreamer assembly  144 . The control module  376  then signals to the solenoid actuator  380  to change state from the retracted position to the extended position. Moving the arm  382  axially downhole presses the set tube  152  downhole into the rolling position. The arm  382  is sized so that, when fully extended, the set tube  152  abuts a downhole stop surface  388 . The combined roller-underreamer assembly  144  is then in the rolling position. 
     To actuate the positioning mechanism  370  a second time, the control module  376  receives a signal to change the state of the combined roller-underreamer assembly  144 . The control module  376  then signals to the solenoid actuator  380  to change state from the extended position to the retracted position. Moving the arm  382  axially uphole pulls the set tube  152  uphole into the reaming position, as shown in  FIG.  21 A . The arm  382  is sized so that, when fully extended, the set tube  152  abuts an uphole stop surface  390 . The combined roller-underreamer assembly  144  is then in the reaming position. 
     In some drilling systems, the body is formed with the drill pipe of the drill string and the body has no first attachment end. In some drilling systems, the body is formed with the drill bit of the drill string and the body has no second attachment end. In some systems, the second attachment end connects to a components other than the drill bit, for example a second drill pipe or other drilling tool. 
     In some underreamers, the control tube is arranged downhole in the reaming position and is arranged uphole in the rolling position. In some reamer arms, the central hinge is arranged such that the central hinge is closer to either the first end or the second end. In some roller arms, the central hinge is arranged such that the central hinge is closer to either the first end or the second end. In some underreamers, the first, second, and third ring are attached such that the underreamer is free to rotate relative to the body in the reaming position and is rotationally constrained to the body in the rolling position. In some underreamers the first, second, and third ring are attached such that the underreamer is free to move axially relative to the body in the rolling position and is axially constrained to the body in the reaming position. 
     In some bottom hole assemblies the at least one of the underreamer, the spring ring, and the spool ring is translatable and/or rotatable relative to the drill string and axially and/or rotationally lockable relative to the drill string. 
     In some spring rings, spikes extend from the outer surface of the spring ring to better engage the walls of the wellbore. 
     Some positioning and actuating mechanisms include sensors in electronic communication with a signal receiver at the surface. The sensors send positioning information to the receiver, for example, confirmation of or information about the position of the underreamer, spring ring, or spool ring. Some guide paths have patterns with more or less than 5 positions. Some guide paths include multiple patterns. Some guide paths have patterns that do not repeat or repeat a distinct number of times. Some cams are arranged on the body and some guide paths is arranged on a plate or guide tube aligned to engage the cam. The guide tube is axially constrained to the control element and finger but is free to rotate relative to the control element and finger. 
     Some spools rings include spool sensor that determines the presence of the fabric and/or determines if the spools are rotating. 
     Some bottom hole assemblies include sensors that determine the distance between the sensor and the walls of the wellbore. 
     Some bottom hole assemblies are rotatable relative to the drill pipe and/or drill bit. 
     In some bottom hole assemblies, the lost circulation fabric covers a portion of the wellbore. In some spools rings, the spools are a single spool that extends around the circumference of the base. The single spool may be coiled relative to the vertical axis so that the ends of the lost circulation fabric overlap when deployed. 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.