BR-112022008274-B1 - PROCESSES AND CONFIGURATIONS FOR EXTRACTING UNDERGROUND RESOURCES

BR112022008274B1BR 112022008274 B1BR112022008274 B1BR 112022008274B1BR-112022008274-B1

Abstract

PROCESSES AND CONFIGURATIONS FOR GROUNDWATER RESOURCE EXTRACTION. Processes and configurations for groundwater resource extraction are described. The processes include the installation of well strings, such as by drilling a plurality of wells, for example, first and second wells, extending from a surface region to a resource deposit. The first and second wells are situated adjacent to each other. Portions of the first and second wells extend laterally, in a manner such as an annular compartment, and connect terminally in a nodal space located within the resource deposit. Carrier fluid is injected from the surface along fluid paths defined by the wells to leach in situ resource materials from the resource deposit into the carrier fluid, and the carrier fluid containing the resource materials is brought back to the surface for resource extraction.

Inventors

BRADLEY V.A. FETTIS
DONALD JOSEPH LARMOUR
DON JOHN GENDZWILL

Assignees

102062448 SASKATCHEWAN LTD

Dates

Publication Date: 20260310
Application Date: 20201030
Priority Date: 20191101

Claims (20)

1. Process for extracting underground resources in situ from underground space, characterized in that it comprises a resource deposit from the extraction of a resource from the resource deposit using a well configuration comprising: a) a first well string extending downwards from a surface region to the resource deposit, the first well string comprising first and second sections, the first section extending downwards from the surface region and the second section extending laterally in a first lateral direction from the first section to the resource deposit; (b) a second well string extending downward from the surface region to the resource deposit, the second well string situated adjacent to the first well string and comprising first and second sections, the first section extending downward from the surface region and the second section extending laterally in a second lateral direction from the first section of the second well string to the resource deposit, wherein proximal portions of the second sections of the first and second well strings curve away from each other and then extend penannularly to form a first flat region and to connect distally in a nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) so that a fluid path (210) is formed downward from the surface region through the first well string to the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) and from the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) upwards to the surface region through the second well string, wherein the process comprises: (i) injecting a carrier fluid (F) from the surface region downwards through the first or second well string along the fluid path (210) in order to leach in situ the resource material from the resource deposit into the carrier fluid (F) and increase the internal volumes of the second sections of the first and second well strings, (ii) circulating the carrier fluid (F) comprising the material of leached resource along the fluid path (210) through the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) and upwards to the surface region through the second well string when injecting the carrier fluid (F) through the first well string or through the first well string when injecting the carrier fluid (F) through the second well string; and (iii) recover the carrier fluid (F) comprising the leached resource material in situ.
2. A process according to claim 1, characterized in that the first section of the first well string and the first section of the second well string extend substantially perpendicular to the surface region, and in that the second sections of the first and second well strings generally extend in a horizontal direction relative to the surface region and the first flat region is situated substantially parallel to the surface region.
3. Process, according to claim 1, characterized in that each second section has an average length and height and width along its length and the circulation of the carrier fluid (F) continues until the internal volumes of the second sections of the first and second well strings have increased so that the average height along the lengths of the second sections of the first and second well strings has increased at least twice, while the average widths along the lengths of the second sections of the first and second well strings have increased at least as much as the increases in heights.
4. Process according to claim 1, characterized in that each second section has a length and an average width along the length, and the circulation of the carrier fluid (F) continues until the internal volumes of the second sections of the first and second well strings have increased such that an average width along the lengths of the second sections of the first and second well strings has increased at least twice from the initial widths of those sections and, subsequently, the process comprises stopping the circulation of the carrier fluid (F) and keeping the carrier fluid (F) stagnant within the second sections of the first and second well strings for a period of at least one day, before recovering the carrier fluid (F) through the first and/or second well string.
5. Process according to claim 1, characterized in that the well configuration comprises first and second well strings comprising casing along a proximal portion of the second section of the first well string or the second section of the second well string.
6. Process according to claim 1, characterized in that the process comprises periodically injecting the carrier fluid (F) alternately through the first and second well strings.
7. Process according to claim 1, characterized in that the well configuration comprises a third well string extending downward from the surface region, the third well string connecting distally in the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460), wherein the first and second well strings have well string openings (105°, 110°, 115°) and wherein the third well string has a surface well string opening (105°, 110°, 115°) adjacent to or distant from the surface well string openings (105°, 110°, 115°) of the first and second well strings.
8. Process according to claim 7, characterized in that the process comprises performing a test of the underground resource deposit for the presence of resource material by accessing the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) through the third well string with a test device before injecting the carrier fluid (F).
9. Process according to claim 7, characterized in that the process comprises injecting the carrier fluid (F) from the surface region into the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) through the third well string and up to the surface region through the fluid path (210) along the first well string or the second well string.
10. Process, according to claim 1, characterized in that: the first well string comprises a third section extending laterally in a third lateral direction from the first section of the first well string to the resource deposit, the second and third sections of the first well string each having an internal volume; the second well string comprises a third section extending laterally in a fourth lateral direction from the first section of the second well string to the resource deposit, the second and third sections of the second well string each having an internal volume, where the third sections of the first and second well strings are formed to extend penannularly to form a second planar region and to connect distally to form a second nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) so that a second fluid path (210) is formed downward from the surface region through the first well string to the second nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) and from the second nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) upwards to the surface region through the second well string; The process further comprises: injecting the carrier fluid (F) from the surface region downwards through the first or second well string along the first and second fluid paths to leach resource material from the in situ resource deposit and increase the internal volumes of the second and third sections of the first and second well strings, and circulating the carrier fluid (F) comprising the resource materials along the fluid path (210) and second fluid path (210) through the first and second nodal spaces upwards to the surface region through the second well string when injecting the carrier fluid (F) into the first well string, or through the first well string when injecting the carrier fluid (F) through the second well string, and recovering the carrier fluid (F) comprising the leached resource material in situ.
11. Process according to claim 1, characterized in that the first and second well columns are a first well and a second well, respectively.
12. Process, according to claim 1, characterized in that the first section of the first well string is a first tubular liner and the second section of the first well string is a first well extending laterally from the first tubular liner, the first section of the second well string is a second tubular liner and the second section of the second well string is a second well extending laterally from the second tubular liner, and the first sections of the first and second well strings together are installed in a first well extending from the surface region.
13. Process, according to claim 1, characterized in that the surface region below which the well configuration is implemented is twenty-five square miles or less.
14. Process, according to claim 1, characterized in that: the first well string comprises at least one additional first section extending laterally in at least one lateral first direction, the first section and at least one additional first section, each having an internal volume of the first section of the first well string for resource storage; The second well string comprises at least one additional second section extending laterally in at least one first lateral direction from the first section of the second well string to the resource deposit, the second section and at least one additional second section each having an internal volume, wherein the at least one additional first section is equal in number to the at least one additional second section, each section of the at least one additional first section penannularly extending with a section of the at least one additional second section to form a plurality of planar regions, and distally connecting to form a plurality of nodal spaces so that a plurality of fluid paths are formed that flow downward from the surface region through the first well string to each of the nodal spaces and from the plurality of nodal spaces upward to the surface through the second well string; and the process further comprises: injecting the carrier fluid (F) from the surface region downward through the first well string or the second well string along the plurality of fluid paths to thereby leach in situ resource material from the resource deposit and increase the internal volume of the first section and at least one additional first section and the second section and at least one additional second section, and circulate the carrier fluid (F) comprising the resource materials along the plurality of fluid paths through the plurality of nodal spaces and upward to the surface through the second well string when injecting the carrier fluid (F) into the first well string, or through the first well string when injecting the carrier fluid (F) through the second well string, thereby recovering the carrier fluid (F) comprising the leached resource material in situ.
15. Process, according to claim 14, characterized in that a plurality of additional well columns, each having a first and a second section, the first section of the additional well columns extending downwards from the surface region and the second section of the additional well columns extending laterally in a first lateral direction from the first section to the resource deposit, and each of the plurality of additional well columns connecting distally to one of the plurality of nodal spaces.
16. Process according to claim 15, characterized in that the process comprises a step (i) comprising injecting the carrier fluid (F) alternately through the first well string and the second well string and/or wherein the process comprises a step (ii) comprising injecting the carrier fluid (F) from the surface region into the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) through one or more of the plurality of additional well strings and up to the surface region through the fluid path (210) along the first and second well strings wherein when step (i) and step (ii) are both conducted, step (ii) is conducted after step (i).
17. A process according to claim 15, characterized in that the first sections of a first plurality of additional well strings correspond to an equal first plurality of tubular casings and the second sections of the first plurality of additional well strings correspond to an equal plurality of laterally extending well strings extending from the first plurality of tubular casings, the first sections of a second plurality of additional well strings correspond to an equal second plurality of tubular casings and the second sections of the second plurality of additional well strings correspond to an equal plurality of laterally extending well strings extending from the second plurality of tubular casings, wherein the plurality of additional well strings are spaced from each other and from the first and second well strings; or wherein the plurality of additional well strings is radially arranged with respect to the first and second well strings.
18. Process according to claim 1, characterized in that the resource material comprises first and second chemical constituents, and the process comprises circulating the carrier fluid (F) in which the first chemical constituent leaches in situ into the carrier fluid (F), and the second chemical constituent is retained in situ and forms a porous matrix.
19. Process according to claim 1, characterized in that the carrier fluid (F) is a solvent and the resource material is solvent-soluble potash.
20. Process for constructing a mining setup for extracting underground resources from a resource deposit, the process characterized in that it comprises: installing a plurality of shaft strings extending downwards from a surface region by: installing a first shaft string extending downwards from the surface region to the mineral deposit, the first shaft string comprising first and second sections, the first section extending downwards from the surface region and the second section extending laterally in a first lateral direction from the first section to the resource deposit; Install a second well string extending downwards from the surface region to the resource pool, the second well string situated adjacent to the first well string and comprising first and second sections, the first section extending downwards from the surface region and the second section extending laterally in a second lateral direction from the first section of the second well string to the resource pool, wherein the second sections of the first and second well strings extend penannularly to form a first planar region and to connect distally in a nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) to thereby form a fluid path (210) downwards from the surface region through the first well string to the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) and the nodal space (120, 310, 320, 420, 421, 422, 423, 424, 425, 426, 427, 450, 460) upwards to the surface through the second well string.

Description

Related Orders [001] This application claims the benefit of U.S. Provisional Patent Application No. 62/929,705, filed November 1, 2019; the entire contents of Patent Application 62/929,705 are incorporated herein by reference. Description Field [002] The present description generally refers to resource extraction and, in particular, to processes and configurations for underground resource extraction. Fundamentals [003] The following paragraphs are provided by way of context for the present description. They are not, however, an admission that anything discussed therein is prior technique or part of the knowledge of persons skilled in the art. [004] Several techniques have evolved to extract and recover valuable underground resources, including mineral resources such as potassium, for example, from geological formations. One such technique, commonly referred to as in situ leaching, involves drilling holes from the surface into an underground resource deposit, and subsequently injecting a surface fluid into the hole to leach the resource material in situ from the deposit into the fluid for recovery at the surface. It can be said that significant benefits can be provided by resource extraction based on in situ leaching compared to more traditional underground mining practices. Thus, for example, resource extraction involving in situ leaching does not require the deployment of an underground workforce, only a limited amount of underground rock material needs to be removed, and the capital costs associated with resource extraction based on in situ leaching are generally lower than those associated with conventional mining or resource extraction operations. [005] For example, the performance of known primary potash mining techniques commonly involves initially forming an underground cavern at the distal end of a vertically oriented borehole. Subsequently, primary resource extraction can be initiated from the underground cavern. This may involve breaking up layers of the resource deposit, a process commonly referred to as rubblizing, to create rubblized resource material that has an enlarged surface area, and then injecting a fluid, such as an unsaturated freshwater solvent, to dissolve the soluble resource material. The solvent fluid may be slowly pumped downstream from the surface into the borehole, for example, through a liner in the hole, towards the cavern. Dissolving resource material in the cavern in the solvent usually results in the formation of a brine. Once the concentration of resource material in the brine is sufficiently high, more solvent is injected from the surface and the brine is circulated to the surface, for example, through the borehole. A fluid flow rate through the cavern can be established to continuously discharge the brine onto the surface. At the surface, the brine can then be processed to recover resource material, and residual minerals, such as salt, are disposed of, typically in a surface tailings area. [006] Thus, a typical resource extraction setup for in situ leaching resource extraction involves a vertically extended shaft comprising a distally situated underground cavern from which resource material is leached and extracted. [007] Primary extraction of potassium mining resources using known techniques and configurations generally requires large land surface areas; for example, large resource leaching operations may contain 40 pits spread over ten or more square kilometers, thus having a significant environmental impact. At the same time, large quantities of the total resource content of underground resource deposits remain unmined using mining techniques known to those skilled in the art. Furthermore, as noted, residual minerals are brought to the surface using conventional potassium extraction techniques. Thus, at the surface, separation of resource material and residual minerals is necessary. Tailings areas require more surface space. In addition, under aeolian conditions, mineral material residues can escape from the tailings area and cause environmental contamination. [008] Furthermore, many operational parameters and resource deposit properties affect the efficiency of an in situ resource extraction operation, including, for example, solvent flow rate, solvent temperature, resource deposit temperature, brine salinity, and cave geometry. Using known systems and techniques for in situ resource extraction, it is challenging to monitor or control these parameters and properties, resulting in a less-than-ideal recovery of minerals from the resource material of the underground resource deposit. [009] Thus, despite the availability of a variety of techniques for recovering materials from underground resource deposits, the known techniques are insufficiently effective. There is a continuing need in the state of the art for improved resource recovery processes from resource deposits and, in particular, there is a need for improved techniques and settings for in situ resource recover