Zone isolation assembly for isolating a fluid zone in a subsurface well

Abstract

A zone isolation assembly (22) for a subsurface well (12) that includes a riser pipe (30) having a fluid zone includes a movable docking receiver (48), a fluid inlet structure (31) and a sealer (56). The docking receiver (48) is adapted to be positioned within the riser pipe (30). The fluid inlet structure (31) is coupled to the docking receiver (48). The fluid inlet structure (31) allows a first fluid from the fluid zone into the fluid inlet structure (31). The sealer (56) is coupled to the docking receiver (48). The sealer (56) selectively forms a seal with the riser pipe (30) to divide the fluid zone into a first zone (26) and a second zone (28) when the sealer (56) is in a first position. In the first position, the first zone (26) is not in fluid communication with the second zone (28).

Description

BACKGROUND

Standard installation procedures for subsurface wells (sometimes referred to herein simply as “wells”) have been established in the environmental industry. In the early years following the establishment of the US EPA program in the US (ca. 1980), many monitoring wells were of 4-inch diameter or greater for the purpose of accommodating readily available fluid pumps that were used in the water resources business, for example, these pumps being of 3-inch diameter and greater. In the mid to late 1980s, smaller diameter pumps were developed specifically for groundwater monitoring applications. As a result, the environmental industry found it possible to reduce monitoring well installation costs by installing 2-inch diameter monitoring wells to accommodate these smaller diameter fluid purging and sampling pumps. Drilling machines that were used for the 2-inch and greater diameter wells were typically auger, rotary or casing drive based technologies—such as hollow stem auger, mud rotary and air rotary, air rotary casing hammer, dual wall percussion and even sonic. These drilling technologies often remove large quantities of soil, rock, and formation fluid to advance a well bore. The costs associated with drilling, containerizing and disposing of these materials can be significant.

Given the expense of using these large drilling machines, direct push drilling technology emerged as a viable technology in the early 1990s—making it possible to reduce costs even further for shallow drilling projects typically ranging between 10 to 60 feet below ground surface (and even deeper with cone penetrometer (CPT) machines) . One feature of the direct push drilling method was the minimization of drill cuttings and fluids by means of simply displacing the unconsolidated sediment to the side of a drive cone or point during borehole advancement, as opposed to removing the cuttings and fluids from the borehole. A key requirement in accomplishing this procedure was to reduce the diameter of the drive cone and drive rod to diameters typically less than 1.5 to 2-inches in order to reduce frictional surface area which is critical for direct push borehole advancement. As a result of the direct push technology, relatively small diameter monitoring wells could be installed to shallow depths at significant cost savings compared to 2-inch and 4-inch monitoring wells installed with more traditional drilling technologies (described above).

Fluid monitoring wells consist of a riser pipe with attached fluid inlet structure at the bottom end of the riser pipe, and are normally of a diameter of at least 2 inches. They are installed in the ground to the depth of the fluid to be sampled and with the fluid inlet structure being of an appropriate length. Once the well structure is in place with the desired configuration, fluid from one zone flows into the riser pipe and rises to an equilibrium point within the pipe. Fluid is then sampled from within the riser pipe using various methods. Unfortunately, a problem with the above-described drilling technologies is that there is no isolation of well bore fluids between the riser pipe and fluid inlet structure of the fluid monitoring well, regardless of diameter.

With conventional technology, it is difficult or impossible to cost-effectively and properly isolate the standing fluid in the riser pipe from the desired fluid in the fluid inlet structure. Therefore, it is entirely possible for the stagnant and possibly non-representative fluid in the riser pipe to mix with the fluid in the fluid inlet structure during purging and sampling, whereby the collected fluid samples may be altered or biased to a non-representative result.

In an effort to reduce the negative impact to these fluid samples and increase the likelihood of relatively representative results, environmental regulations within the fluid monitoring industry require certain amounts of fluid be purged from the riser pipe prior to sampling to remove stagnant standing fluid and/or fluid that is non-representative. Many branches of state and local environmental agencies still require that at least 3 to 5 wet casing volumes are removed from the well structure as a means of eliminating all of the stagnant and non representative fluid from the fluid inlet structure and riser pipe zones. Hence, there is significant fluid drawdown inside the well to facilitate this process. As stagnant and/or non representative fluid is removed, new fluid is drawn into the riser pipe from the fluid inlet structure. In theory, the intent of this process is to increase the likelihood that fluid samples taken statistically reflect actual fluid conditions. The downside to using this procedure, however, is that it is necessary to remove significant quantities of fluid (purging) at a substantial cost.

Many state and local agencies now allow a procedure called “low-flow sampling” as a common practice for the purpose of reducing the amount of fluid purged when using 3 to 5 wet casing volumes. Low-flow sampling requires that the fluid within the riser pipe not be drawn down significantly during the sampling event; therefore, the recharge rate of fluid into the riser pipe from the intake area must be nearly equal to the rate of fluid discharged during purging and sampling. This can require monitoring of actual drawdown during sampling by means of an electrical or fiber optic transducer inserted into the well to detect changes in fluid level.

Wells can also be used for fluid extraction for the purpose of remediation, i.e. to remove and/or treat fluid or other fluid contaminants. Pumping devices, systems and methods (similar to those described in this application) can be adapted for the purposes of remediation as well.

SUMMARY

The present invention is directed toward a zone isolation assembly for a subsurface well. The subsurface well includes a riser pipe having a fluid zone. In one embodiment, the zone isolation assembly includes a movable docking receiver, a fluid inlet structure and a sealer. In certain embodiments, the docking receiver is adapted to be positioned within or adjacent to the riser pipe. The fluid inlet structure can be coupled to the docking receiver. The fluid inlet structure allows a fluid from the fluid zone into the fluid inlet structure. The sealer can be coupled to the docking receiver. The sealer selectively forms a seal with the riser pipe to divide the fluid zone into a first fluid zone and a second fluid zone when the seal is in a first position. In the first position, the first fluid zone is not in fluid communication with the second fluid zone.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIGS. 1A-D are schematic views of a portion of a fluid monitoring system including a zone isolation assembly having features of the present invention;

FIGS. 2A-D are schematic views of another embodiment of a portion of the fluid monitoring system;

FIGS. 3A-D are schematic views of yet another embodiment of a portion of the fluid monitoring system;

FIGS. 4A-D are schematic views of still another embodiment of a portion of the fluid monitoring system;

FIGS. 5A-D are schematic views of another embodiment of a portion of the fluid monitoring system;

FIGS. 6A-D are schematic views of yet another embodiment of a portion of the fluid monitoring system;

FIGS. 7A-D are schematic views of still another embodiment of a portion of the fluid monitoring system;

FIGS. 8A-D are schematic views of another embodiment of a portion of the fluid monitoring system;

FIGS. 9A-D are schematic views of yet another embodiment of a portion of the fluid monitoring system;

FIGS. 10A-D are schematic views of still another embodiment of a portion of the fluid monitoring system;

FIGS. 11A-D are schematic views of another embodiment of a portion of the fluid monitoring system;

FIG. 12 is a perspective view of one embodiment of a docking receiver of the zone isolation assembly;

FIG. 13 is a perspective view of another embodiment of a docking receiver of the zone isolation assembly;

FIG. 14 is a perspective view of yet another embodiment of a docking receiver of the zone isolation assembly;

FIG. 15 is a schematic view illustrating operation of a pump of the zone isolation assembly;

FIG. 16 illustrates various views of one embodiment of the pump;

FIGS. 17A-D are various views of a docking apparatus and a docking receiver having features of the present invention;

FIGS. 18A-C are schematic views of an embodiment of the docking apparatus and the docking receiver;

FIG. 19 illustrates schematic views of a portion of one embodiment of the fluid monitoring system; and

FIG. 20 is a schematic view of one embodiment of the fluid monitoring system.

DESCRIPTION

The present invention includes well conversion and retrofit technology to substantially reduce purge volumes in fluid monitoring systems 10 including subsurface wells 12 and/or to isolate sampling and fluid sensor targets with integrated purging and sampling devices as described herein.

Certain embodiments address one or more of the following well conversion and retrofit concepts:

• • 1. The means for retrofitting existing fluid, e.g., groundwater monitoring wells (of any diameter) with a permanent or removable zone isolation assembly 22, with integrated zone isolation equipment (such as various types of mechanical and/or pneumatic sealers 56) used to isolate the sampling zone of interest (also sometimes referred to herein as the “first zone 26”) from a second zone 28 to increase the likelihood that fluid intake is restricted to one or more first zone(s) 26 or variations thereof, and to reduce or eliminate cross-communication and drawdown of non-target zone fluids inside the well structure of concern during the purging and sampling process.
  • 2. The means for docking a flexible or rigid, removable zone isolation assembly 22, which can include one or more bladder pumps, electrical pumps, single valve pneumatic lift and gas displacement pumps, dual valve pneumatically actuated hydraulic lift pumps, double piston and single piston pumps, passive diffusion bags, bailers of any type including pressurized bailers, and any other type of grab sampling device such as SNAP samplers, HydroSleeves, etc., and that one or more of these methods and apparatus are outfitted with a docking receiver 48 and/or a docking apparatus 50 that allows these devices to be received and/or sealed within the zone isolation assembly. The seal between the docking apparatus 50 and the docking receiver 48 is configured to reduce or eliminate fluid communication between two adjacent zones within the well structure or well bore.
  • 3. A method and device for docking an independent sensor device (such as pressure, temperature, and/or chemical sensor, as non-exclusive examples) or sensor device coupled with a fluid collector directly with the docking receiver 48 that is connected to an isolated area of a well.
  • 4. Simultaneous purging, sampling and sensing capabilities for multiple wells 12 containing the extraction systems described herein, and within U.S. patent application Ser. No. 11/651,647 filed on Jan. 9, 2007, by Noah R. Heller and Peter F. Moritzburke, entitled “Zone Isolation Assembly Array For Isolating a Plurality of Fluid Zones In a Subsurface Well”, the contents of which are incorporated herein by reference.

Existing or new fluid monitoring wells 12 of any diameter can be retrofitted with a permanent or removable zone isolation assembly 22. The zone isolation assembly 22 can include integrated zone isolation equipment (such as various types of mechanical pneumatic and electrical sealing devices or any combination thereof used to isolate the sampling zone of interest to increase the likelihood that fluid intake is restricted to one or more sampling target zone(s) or variations thereof, and to reduce cross-communication and drawdown of non-target zone fluids inside the well structure of concern during the purging and sampling process. These integrated zone isolation assemblies 22 can be placed within well structures as a single-zone or a multi-zone isolation assembly. See FIGS. 1 through 10. FIG. 11 shows a variation of FIG. 10 (without the docking receiver 48). FIGS. 12 through 14 show the mechanical structure and function of the docking receptacle.

• • 1. A flexible or rigid, removable fluid collector 52 is docked with a docking receiver 48, the fluid collector 52 including one or more various methods and apparatuses, including as non-exclusive examples, bladder pumps, electrical pumps, single valve pneumatic lift and gas displacement pumps, dual valve pneumatically actuated hydraulic lift pumps, double piston and single piston pumps, passive diffusion bags, bailers of any type including pressurized bailers, and any other type of grab sampling device such as SNAP samplers, HydroSleeves, etc., and that one or more of these methods and apparatuses are outfitted with a docking apparatus 50 described in this document that allows these devices to be received and sealed by the engaging docking receiver 48 constructed within the zone isolation assembly 22. The seal between the docking apparatus 50 and the docking receiver 48 is such that there is substantially no communication with fluids within the well structure or well bore that are located above the docking receiver 48 that can communicate with the purged and sampled fluids from a target zone area 26. FIGS. 15 through 17 illustrate the outlay of one docking apparatus 50 and how it docks with the docking receiver 48.
  • 2. A method and device for docking an independent sensor device 54 (such as pressure, temperature, and/or chemical sensor, as non-exclusive examples) or any other suitable sensor device 54 coupled with any docking apparatus 50 directly with a docking receiver 48 that is connected to an isolated area of a well 12, as illustrated in FIGS. 18 and 19.
  • 3. Simultaneous purging, sampling and sensing capabilities for multiple wells 12 containing the extraction systems described herein and within U.S. patent application Ser. No. 11/651,647 filed on Jan. 9, 2007, by Noah R. Heller and Peter F. Moritzburke, entitled “Zone Isolation Assembly Array For Isolating a Plurality of Fluid Zones in a Subsurface Well”, as illustrated in FIG. 20.

Sealers 56, such as packers as one non-exclusive example, can be constructed of materials that will pass through an outer riser pipe 30 of the original well 12 and the fluid within the outer riser pipe 30 to the desired depth just above a fluid inlet structure 29 and are of various types of construction and materials. These sealers 56 can include bentonite packers, gasket packers, expandable flange packers, collapsing fluid filled bag packers (with and without pneumatic pressurization assist), or any other suitable type of mechanical, pneumatic and electric packers, as well as any combination thereof. Each sealer 56 can provide the ability to form a seal between a section of an inner riser pipe 32 positioned just below the docking receiver 48 and an inner wall of the outer riser pipe 30 (typically located at a position just above the fluid inlet structure 29). The sealer 56, in part, isolates the first zone 26 from the second zone 28 within the outer riser pipe 30. See FIGS. 1 through 9, for example. Any of these sealers 56 can be used as a single location seal or as a double or straddle packer device, such as that illustrated in FIGS. 10 and 11, for example.

A variety of sealers 56 can be used with the zone isolation assembly described herein, including a flexible elastic packer with multiple flanges to seal against retrofitted riser pipe 30 wall (FIGS. 5, 10, and 11). The packer, or packers, in series for maximum sealing, would be located just below the docking receiver 48 to form a seal around the inner riser pipe 32 below the docking receiver 48 and between the fluid inlet structure 29 of the retrofitted well and the outer riser pipe 30 of the retrofitted well.

A rigid deployment device 58 (FIGS. 12-14) is inserted into the outer riser pipe 30 and the zone isolation assembly 22 is lowered into position such that the sealer 56 is above the fluid inlet structure 29 in the retrofitted well. Slotted pipe or filter is attached to the underside of the docking receiver 48 to allow fluid to be extracted only from the first zone 26 of the retrofitted well.

The pipe or rod attached to the lower end of the slotted pipe or filter can extend to the bottom of the well to allow the operator of the deployment device 58 to know when the system has been lowered to the appropriate depth. An inner fluid inlet structure 31 connected to the bottom of the docking receiver 48 can also can be filled with sand, deionized water, or other substance, and sealed to act as a displacement device to reduce purge volume within the inner fluid inlet structure 31. Also, the pipe can be slotted and filled with sand to allow fluid to pass through the column of sand and up into the docking receiver 48.

An elastic bag, filled with fluid or gas, is located just below the docking receiver 48 to form a seal around the inner riser pipe 32 below the docking receiver 48 and between the fluid inlet structure 29 of the retrofitted well and the outer riser pipe 30 of the retrofitted well.

The bag can be compressed by applying mechanical pressure to form a seal around the inner riser pipe 32 below the docking receiver 48, and between the fluid inlet structure 29 of the retrofitted well and the riser pipe 30 area of the retrofitted well. When deploying, the rigid deployment device is inserted into the docking receiver 48 and the system is lowered down to the desired depth, as signaled by the resistance felt by the operator of the deployment device 58 when the displacement pipe touches the bottom of the well, as illustrated in FIGS. 6, 7, and 8.

One option available when using a sealer 56 such as an elastic bag filled with water is to use the deployment device 58 to apply pressure on the rigid deployment device 58 until a pin in the “J-slot” descends to its lowest point (FIG. 7). The deployment device 58 operator then turns the rigid deployment device 58 and the docking receiver 48 while releasing pressure, and the pin rises to engage the second upward leg of the “J-slot”. The bag is compressed to seal the fluid inlet structure 29 from the area above the docking receiver 48. The resistance of the compressed bag sealed against the well wall will keep the pin engaged in this position.

In cases where removal of the elastic bag packer is required, but for some reason the bag will not disengage from its compressed position, the docking receiver 48 can be constructed with pass-through channels to allow well operators to use a piercing tool to puncture the elastic bag if necessary.

An elastic bag or packer device, filled with fluid or gas, is located just below the docking receiver 48 to form a seal around the inner riser pipe 32 below the docking receiver 48 and between the fluid inlet structure of the retrofitted well and the riser pipe area of the retrofitted well.

An elastic bag packer can be inflated by means of pressure applied through tubing extending from the ground surface, through a pass-through in the docking receiver 48, to the sealer 56 (FIG. 8). When deploying, the deployment device 58 is inserted into the docking receiver 48 and the system is lowered down to the desired depth, as signaled by the resistance felt by the operator when the pipe or rod below the slotted screen touches the bottom of the well. Pneumatic pressure is then applied to the tubing to inflate the sealer 56.

The pipe or rod attached to the lower end of the slotted pipe or filter can extend to the bottom of the well to allow the deployment device 58 operator to sense when the system has been lowered to the appropriate depth. The pipe also can be filled with sand, deionized water, or other substance, and sealed to act as a displacement device to reduce purge volume within the fluid inlet structure. Also, the pipe can be slotted and filled with sand to allow fluid to pass through the column of sand and up into the docking receiver 48. The docking receiver 48 can be constructed to have pass-through holes to allow well operators to use a piercing tool to puncture the packer if necessary.

Filter sock containing bentonite pellets, or other sealing agent, below receptacle above intake screen. The system is designed to have a docking receiver 48 above a length of riser pipe around which a porous sack containing bentonite, or other agent that expands with hydration, is placed (FIGS. 1, 2, 3 and 11). The collar at the bottom of the riser pipe supports the sack and prevents it from dropping down onto the slotted section of riser pipe. The slotted riser pipe or filter below the collar extends down to the bottom of the well. The sack may also be independently suspended without collars from the length of riser pipe below the docking receiver 48.

When the system is lowered into place, the substance within the sack is hydrated over time and expands to form an impermeable seal between the inside of the retrofitted well and the zone isolation assembly inner riser pipe 32 located just below the docking receiver 48. Fluid within the first zone 26 of the retrofitted well flows into the smaller diameter fluid inlet structure 31 attached to the bottom of the docking receiver 48, then through the docking receiver 48 and directly to the fluid collector 52 of the zone isolation assembly 22.

The pipe or rod attached to the lower end of the slotted pipe or filter can extend to the bottom of the well to allow the deployment device 58 operator of the system to know when the system has been lowered to the appropriate depth. The pipe also can be filled with sand, deionized water, or other substance, and sealed to act as a displacement device to reduce purge volume within the fluid inlet structure. Also, the pipe can be slotted and filled with sand, and with or without a “sipping tube” inserted within the slotted pipe, to allow fluid to pass through the column of sand and up through the riser pipe into the docking receiver 48. See FIGS. 1-7.

The system is operated by deploying a pump, or an integrated sensor and pump system, or sensor alone, to seat with the docking receiver 48. The pump seals with the docking receiver 48, and extracts fluid from the screen below the docking receiver 48 and delivers it to the ground surface. The sensor can detect and record pressure, temperature, or any other relevant parameters directly within the isolated fluid inlet structure.

Some advantages of this zone isolation device and methodology can include one or more of the following:

• • 1. Ability to be used in any size pipe—including miniaturization to allow use within small-diameter pipe, including all pipe sizes below 2 inches in diameter.
  • 2. Flexibility of the mechanical packer sealing mechanism to facilitate insertion and deployment to depth within any diameter pipe including small-diameter pipes.
  • 3. Integration with a flexible, removable fluid sampling system.
  • 4. Prevention of drawdown of fluid within the riser pipe during sampling events. This reduces or eliminates the need for fluid level sensors to monitor and verify drawdown.
  • 5. Isolation of a specific area of the riser pipe to target the sampling zone of interest. This may reduce the purging requirement prior to sampling, and provides verification that samples are being taken from the zone of interest.
  • 6. Providing an economic and effective alternative to more expensive and cumbersome zone isolation techniques, including inflatable packers.

To provide the benefits sampling capabilities within narrowly targeted regions of a well, existing wells can be retrofitted with smaller diameter riser pipe that has a packer to isolate the zone below the packer and immediately above the bottom of the riser pipe. The riser pipe can be fitted with a docking receiver 48 and screen or filter within the screened zone of the retrofitted well (located below the zone isolation assembly packer) to integrate a fluid sampling device. That sampling device is described in this application, and applies to those described within U.S. patent application Ser. No. 11/651,900 filed on Jan. 9, 2007, by Noah R. Heller and Peter F. Moritzburke, entitled “Zone Isolation Assembly for Isolating and Testing Fluid Samples from a Subsurface Well” as well. The riser pipe may also have multiple packers to isolate intermediate zones within a well, as well as docking receptacles and screens or filters.

Riser pipe with flexible mechanical packers fitted to the outside of the pipe, or at the joints between lengths of pipe, is inserted into an existing well to the depth of the screened zone of interest, such that the packer is just above that screened zone. The docking receiver 48 can be integrated into the riser pipe at a joint between lengths of the riser pipe, or within the continuous riser pipe itself, and is used to seat a fluid extracting device. The filter or slotted screen below or between the packers allows fluid to enter the riser pipe only from the zone isolated by the packers within the retrofitted well.

The system is operated by activating the pump or other monitoring or sampling devices seated in the docking receiver 48. The monitoring and sampling devices extract, sense, or otherwise sample fluid from the screen below the docking receiver 48.

Retrofitting existing wells with smaller diameter riser pipe with the features described here has one or more of the following features:

• • 1. Limiting purge volume required when purging and sampling to meet regulatory and other guidelines.
  • 2. Isolating and drawing substantially exclusively from the zone of interest within the larger diameter well being retrofitted.
  • 3. Integrating unique docking and pumping features described in the present Application and U.S. patent application Ser. No. 11/651,900 filed on Jan. 9, 2007, by Noah R. Heller and Peter F. Moritzburke, entitled “Zone Isolation Assembly for Isolating and Testing Fluid Samples from a Subsurface Well” into existing wells of larger diameter.

To provide the benefits of sampling capabilities within targeted regions of a well, existing wells can be retrofitted with a device that has a docking receiver 48 and a packer to isolate the zone below the packer and immediately above the bottom of the riser pipe. The docking receiver 48, and with attached screen or filter within the surrounding screened zone of the retrofitted well, is designed to integrate any type of sampling device including but not limited to bladder pumps, electrical pumps, single valve pneumatic lift and gas displacement pumps, dual valve pneumatically actuated hydraulic lift pumps, double piston and single piston pumps, passive diffusion bags, bailers of any type including pressurized bailers, and any other type of grab sampling device such as SNAP samplers, HydroSleeves, etc., such that all of these methods and apparatus are outfitted with a docking mechanism described in this document that allows these devices to be received and sealed by the docking receiver 48 constructed within the zone isolation assembly. The deployable docking receiver 48 may also have multiple packers to isolate intermediate zones within a well, as well as docking receiver 48 and screens or filters.

A zone isolation assembly 22 fitted with one or more sealers 56 is inserted into an existing well to the depth of the screened zone of interest, such that the packer is just above that screened zone. The docking receiver 48 is used to seat a fluid extracting device. Below the docking receiver 48 is a slotted screen or filter through which fluid is drawn directly from the screened zone isolated by the packers. The fluid and fluid pressure within the screened zone is isolated from the well area above the packer.

The zone isolation assembly 22 is deployed by connecting the system to a rigid device being used to insert the assembly to the desired depth within the well above the fluid inlet structure. Lengths of connected pipe with diameter smaller than the internal diameter of the well being retrofitted can be used.

The docking receiver 48 has a slotted cylinder with an internal insert pin groove located within the wall of the pump receptacle into which the docking end of the deployment device 58 can connect or seat (FIGS. 12-14). An end piece of the rigid deployment device 58 has two insert pins that can be spaced approximately 180 degrees apart, for example, that fit into the internal insert pin groove of the slotted cylinder. In one embodiment, travel of the insert pins to the internal insert pin groove can be conveyed through two substantially similar or identical (female) insert slots located at the top of the docking receiver 48 that are spaced approximately 180 degrees apart and correspond geometrically to the location of the insert pins. Once inserted, the end piece of the deployment device 58 is rotated approximately 90 degrees such that each of the insert pins reaches two corresponding groove recesses that are spaced approximately 180 degrees apart. At this point, the insert pins are allowed to move upward into the internal groove recesses—fixing the position of the deployment device 58 during descent to the drop-off point inside the retrofitted well. Therefore, the docking receiver 48 is gravitationally seated and suspended onto the deployment device 58 insert pins during substantially the entire descent to the target depth. For retrieving the system, the end piece of the deployment device 58 is lowered to the top of the docking receiver 48 and rotated until the insert pins drop into the insert slots. As before, the tool is rotated 90 degrees until the operator physically sees and feels the upward movement of the tool's insert pins slide upwardly into the internal groove recess points. By pulling up on the deployment device 58, the zone isolation assembly 22 can be retrieved to the surface.

This application describes a unique design for various docking apparatuses 50 and/or fluid collectors 52 that have the ability to dock with the docking receiver 48 described herein and include bladder pumps, electrical pumps, single valve pneumatic lift and gas displacement pumps, dual valve pneumatically actuated hydraulic lift pumps, double piston and single piston pumps, passive diffusion bags, bailers of any type including pressurized bailers, and any other type of grab sampling device such as SNAP samplers, HydroSleeves, etc., and that all of these methods and apparatus are outfitted with a docking mechanism 50 described in this document that allows these devices to be received and sealed by the docking receiver 48 constructed within the zone isolation assembly. The seal between the docking apparatus 50 and the docking receiver 48 is such that there is substantially no communication with fluids within the well structure or well bore that are located above the receiving device that can communicate with the purged and sampled fluids from the target zone area. FIGS. 15 through 17 show the outlay of one sampling device and how it docks with the receiving receptacle. These docking apparatuses 50 can share one or more of the following features:

• • 1. An o-ring design for docking with a docking receiver 48 within a fluid well riser pipe to sample fluid directly from the zone of interest; the o-ring sealing mechanism provides a fluid-tight seal, and allows immediate removal of the docking apparatus 50 through direct retrieval of the tubing and/or cable attached to the docking apparatus 50.
  • 2. An o-ring design for preventing cross fluid communication between fluid within the fluid inlet structure from mixing with stagnant or moving fluid within the superjacent riser pipe area.
  • 3. Scalability to any size to conform to any diameter of riser pipe.
  • 4. A unique fluid transfer and assembly design for easy manufacturing and assembly.

To reduce cost and increase effectiveness of fluid sampling, zone isolation assembly pump technology has the ability to dock directly with a docking receiver 48 within the well riser pipe to be retrofitted. This allows the pump to draw fluid directly and exclusively from the sampling zone of interest below the docking receiver 48, and prevents drawdown of fluid within the riser pipe. Drawdown prevention is important in order to prevent dilution or pre-concentration effects from stagnant fluid in the riser pipe of the retrofitted well.

The pump is designed to have an o-ring fitted near the end of the pump to allow the weight of the pump and attached equipment above the pump to produce a fluid-tight seal with the docking receiver 48 (FIGS. 15, 16 and 17). The o-ring end of the pump that seats with the docking receiver 48 has a hole or a protruding tube to allow the fluid to flow directly from the zone of interest through the docking receiver 48 into the pump. The fluid then fills the sample return tubing and the pneumatic pressure tubing up to the equilibrium point as determined by the pressure within the fluid formation.

When the pump o-ring is seated in the docking receiver 48, fluid from the zone of interest does not flow between the riser pipe and the zone of interest below the docking receiver 48. The fluid within the zone of interest flows freely into the riser pipe through the docking receiver 48 when the pump o-ring is not seated in the docking receiver 48.

The miniature seated pump can have two valves. In this embodiment, ‘Valve 1’ prevents displacement of fluid back into the fluid monitoring well while pneumatic pressure is applied to ‘Tubing 1’. ‘Valve 2’ prevents sample fluid from dropping back down the sample return tubing or pipe during repeated pumping cycles. ‘Valve 1’ and ‘Valve 2’ (for example, balls or poppets) move freely up and down within ‘Cavity 1’ and ‘Cavity 2’. Each cavity has an o-ring or sealing seat at the lower end of the cavity.

Fluid introduced from below the docking receiver 48 flows through the end tip of the pump intake or protruding tube into ‘Channel 1’. Fluid flows through ‘Channel 1’then through ‘Valve 1’ then through the perforated holes in ‘Connector’. The interior of the pump has a ‘Circular Channel’ through which sample fluid flows from ‘Channel 1’ and into ‘Channel 2’. The ‘Circular Channel’ is continuous around the upper face of the lower part of the pump. The continuity of the channel is important because the 2 halves of the pump (‘Part A’ and ‘Part B’) can be assembled by screwing each part of the pump onto ‘Connector 1’, and fluid will flow through the channel regardless of the position of ‘Channel 2’ after assembly.

The system is sealed by the o-ring in a groove around the outer body of the ‘Part A’ of the pump. When assembled, the collar on the bottom edge of ‘Part B’ compresses the o-ring, seals the channel, and shoulders against the apposing part of ‘Part A’.

In one embodiment, operating the miniaturized pump with the docking apparatus 50 can include one or more of the following steps:

• • 1. Pneumatic pressure is applied in ‘Tubing 1’. See FIG. 16. ‘Valve 1’ closes to prevent fluid in ‘Tubing 1’ from being pushed back into the zone of interest. Sample fluid in ‘Tubing 1’ and ‘Tubing 2’ is pushed toward the ground surface.
  • 2. After fluid in ‘Tubing 1’ is pushed to the depth of ‘Valve 1’ pneumatic pressure is released from ‘Tubing 1’.
  • 3. ‘Valve 2’ closes to prevent fluid in ‘Tubing 2’ from descending back into the zone of interest below the docking receiver 48.
  • 4. Fluid from the zone of interest below the docking receiver 48 rises to an equilibrium point within ‘Tubing 1’ as determined by pressure from the zone of interest below the docking receiver 48. See FIG. 16.
  • 5. Pneumatic pressure is reapplied to ‘Tubing 1’ and the cycle is repeated. Fluid is returned to the surface in a stream without the introduction of the pneumatic lifting agent to the purged fluid. The pneumatic lifting agent is typically pressurized gas such as nitrogen or ambient air; other fluids may also be used, such as oil or another agent to which pressure can be applied.

The o-ring sealing mechanism between the pump tip and the docking receiver 48 allows the entire pump to be removed easily by retracting the tubing attached to the pump, and/or suspension cable supporting the pump system. The seal with the docking receiver 48 is effectively broken and the pump is retrieved by lifting and retracting the tubing and/or cable.

One or more advantages to this miniature pump and docking mechanism can include:

• • 1. Small size to allow use within small-diameter riser pipe.
  • 2. Integrated o-ring and docking design to allow a fluid-tight seal between the pump and the docking receiver 48. Fluid can flow directly from the zone of interest below the docking receiver 48 through the docking receiver 48 into the pump. When the pump is seated in the docking receiver 48, fluid is essentially not exchanged between the zone of interest and the riser pipe. This prevents draw down of fluid within the riser pipe during pump operation.
  • 3. Designed for time savings during assembly and disassembly. This design decreases product cost, increases efficiency during maintenance, and improves durability due to minimization of moving parts.
  • 4. Sensors, such as temperature or pressure sensors, or other suitable sensors, with and without integrated data storage capability, can be integrated with the pump to collect parameter data directly from the zone of interest below the docking receiver 48.

The docking receiver 48 described herein can be installed within new wells, or within retrofitted wells, and/or can be used to integrate sensors to detect and record well parameter data directly within the isolated zone of interest. The sensor could be deployed without a sampling system, or with an integrated sampling system. Summary features include:

• • 1. Docking receiver 48 designed for partial retraction of sensor to allow fluid transfer from the docking receiver 48 opening to fluid intake ports on sensor housing above the lower sensor o-ring.
  • 2. Single or multiple upper o-rings above the fluid intake ports on sensor housing to seal the upper portion of the sensor housing against the docking receiver 48 to reduce the likelihood of fluid from riser pipe from entering the fluid intake ports below the upper o-rings.
  • 3. Sensor integration to allow fluid to pass through the docking receiver 48 and the sensor housing into the pump while sensor is seated in the docking receiver 48.

The housing designed to contain the sensor has intake ports that substantially do not allow fluid to enter the sensor housing from the upper portion of the well above the docking receiver 48 when the housing is docked in the docking receiver 48. In one configuration, when the housing is fully engaged in the docking receiver 48, the lower o-ring at the end of the housing seals the end opening of the housing against the fluid intake area of the docking receiver 48. This isolates the sensor and allows it to detect parameters such as temperature and pressure, for example, directly within the isolated zone of interest below the interconnected receptacle. See FIG. 18.

When the sensor housing is retracted to disengage the lower o-ring at the end opening from the docking receiver 48 o-ring groove, fluid flows from the docking receiver 48 opening into the intake ports above the lower o-ring. There is an o-ring seal around the end of the sensor inside the housing that reduces the likelihood of back-flow of fluid past the sensor and out the end opening. The fluid then moves up and around the sensor within the housing to an outtake port at the top of the housing.

In another configuration, the sensor (with or without integrated data storage capability) remains seated in the docking receiver 48 with fluid flowing past the sensor tip, through the sensor housing, and into the pump. See FIG. 19. The sensor can detect parameters (temperature, pressure, etc.) within the fluid passing through the docking receiver 48, including fluid within the tubing above the pump. This allows the pressure sensor to function as a fluid level sensor within the well. A miniature pump can be attached to the outtake port at the top of the sensor housing to deliver the fluid to the ground surface.

In the retractable system used for isolating the sensor to detect parameters only in the zone below the docking receiver 48, when engaged within the docking receiver 48, a double o-ring system around the sensor housing allows sensor docking in the fully-deployed position, and fluid extraction in the partially-retracted position.

In the system used for monitoring fluid levels within the well, the sensor housing can be docked in one position for sensor operation and fluid sampling.

The pumping systems described herein and within U.S. patent application Ser. No. 11/651,647 filed on Jan. 9, 2007, by Noah R. Heller and Peter F. Moritzburke, entitled “Zone Isolation Assembly Array for Isolating a Plurality of Fluid Zones In a Subsurface Well”, which are installed in multilevel configurations, or installed in close proximity to one another, can be operated individually or simultaneously, as illustrated in FIG. 20. The simultaneous capability provides significant efficiencies in time savings. This capability is unique among multilevel fluid monitoring and extraction systems with integrated pumping systems.

Subsurface wells that include one or more zone isolation assemblies and/or other well technologies described in this application can be operated independently or simultaneously using a controller with capability to operate multiple well systems. The simultaneous controller may contain multiple timers, pressure regulators, air compressors, compressed gas tanks, fittings, and other equipment typically used for well system operation.

While the particular fluid monitoring system and zone isolation assemblies as herein shown and disclosed in detail, are fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that they are merely illustrative of various embodiments of the invention. No limitations are intended to the details of construction or design herein shown other than as described in the appended claims.

Claims

1. A zone isolation assembly for a subsurface well including a riser pipe having a fluid zone, the zone isolation assembly comprising: a movable docking receiver adapted to be positioned within the riser pipe; a fluid inlet structure that is coupled to the docking receiver, the fluid inlet structure allowing a fluid from the fluid zone into the fluid inlet structure; and a sealer that is coupled to the docking receiver, the sealer selectively moving to a first position wherein the sealer forms a seal with the riser pipe to divide the fluid zone into a first zone and a second zone that is not in fluid communication with the first zone.