Dewatering apparatus, systems, and methods

1 . A sulfur recovery unit dewatering system, comprising:

a sulfur recovery unit configured to extract sulfur from a sour gas produced from a hydrocarbon fluid;

at least one sulfur tank installed at least partially in a subterranean formation, the at least one sulfur tank comprising a top surface at or near a terranean surface, a volume that extends below the terranean surface into the subterranean formation, and a sump that is below a water table level in the subterranean formation at a low tide level, the at least one sulfur tank configured to store the extracted sulfur;

at least one submersible pump positioned in the subterranean formation and in fluid communication with a liquid in the subterranean formation adjacent the at least one sulfur tank;

at least one conduit fluidly coupled to the at least one submersible pump and extending to the terranean surface; and

at least one liquid level sensor positioned in a borehole formed into the subterranean formation adjacent to and separate from the at least one sulfur tank to measure a level of the liquid in the subterranean formation adjacent the at least one sulfur tank and configured, when the measured level exceeds a threshold level, to signal the at least one submersible pump to circulate at least a portion of the liquid from the subterranean formation, into the at least one conduit, and toward the terranean surface.

2 . The sulfur recovery unit dewatering system of claim 1 , wherein the liquid comprises freshwater or brine.

3 . The sulfur recovery unit dewatering system of claim 1 , further comprising a liquid filtration unit fluidly coupled to the at least one conduit and configured to receive the circulated portion of the liquid from the subterranean formation.

4 . The sulfur recovery unit dewatering system of claim 3 , wherein the liquid filtration unit comprises a reverse osmosis filtration unit.

5 . The sulfur recovery unit dewatering system of claim 1 , wherein the threshold level is the low tide level.

6 . The sulfur recovery unit dewatering system of claim 1 , further comprising a controller communicably coupled to the at least one submersible pump and the at least one liquid level sensor, the controller configured to perform operations comprising:

identifying the measured level at the at least one liquid level sensor; and

activating the at least one submersible pump based on the measured level exceeding the threshold level.

7 . The sulfur recovery unit dewatering system of claim 1 , wherein the at least one submersible pump is positioned in the borehole formed from the terranean surface to the subterranean formation.

8 . A method for dewatering a subterranean formation adjacent a sulfur recovery unit, comprising:

providing at least one submersible pump positioned in a subterranean formation adjacent at least one sulfur tank installed at least partially in the subterranean formation, the at least one sulfur tank comprising a top surface at or near a terranean surface, a volume that extends below the terranean surface into the subterranean formation, and a sump that is below a water table level in the subterranean formation at a low tide level, the at least one sulfur tank configured to store sulfur extracted, in a sulfur recovery unit, from a sour gas produced from a hydrocarbon fluid;

sensing, with at least one liquid level sensor positioned in a borehole formed into the subterranean formation adjacent to and separate from the at least one sulfur tank, a level of a liquid in the subterranean formation adjacent the at least one sulfur tank;

determining that the sensed level of the liquid exceeds a threshold level; and

based on the determination, operating the at least one submersible pump to circulate at least a portion of the liquid from the subterranean formation, into at least one conduit fluidly coupled to the at least one submersible pump, and to the terranean surface through the at least one conduit.

9 . The method of claim 8 , wherein the liquid comprises freshwater or brine.

10 . The method of claim 8 , further comprising circulating the portion of the liquid to a liquid filtration unit fluidly coupled to the at least one conduit.

11 . The method of claim 10 , wherein the liquid filtration unit comprises a reverse osmosis filtration unit.

12 . The method of claim 10 , further comprising cleaning the portion of the liquid in the liquid filtration unit.

13 . The method of claim 8 , wherein the threshold level is the low tide level.

14 . The method of claim 8 , further comprising:

sensing, with at least one liquid level sensor, another level of the liquid in the subterranean formation adjacent the at least one sulfur tank;

determining that the another sensed level of the liquid is less than the threshold level; and

based on the determination, stopping operation of the at least one submersible pump.

15 . A dewatering system, comprising:

a subterranean pump positionable in a borehole formed from the terranean surface adjacent a sulfur pit and into a subterranean formation that comprises water, the sulfur pit comprising an opening at the terranean surface and a volume that extends below the terranean surface into the subterranean formation with a low level that is below a water table level in the subterranean formation at a low tide level;

at least one conduit fluidly coupled to the subterranean pump and configured to extend from the pump to a terranean surface;

a water level sensor positionable in the borehole to measure a level of the water in the subterranean formation adjacent the sulfur pit; and

a control system communicably coupled to the subterranean pump and the water level sensor and configured to perform operations comprising:

identifying a water level sensed by the water level sensor,

determining that the water level exceeds a threshold level, and

based on the determination, activating the subterranean pump to remove water from the subterranean formation into the at least one conduit.

16 . The dewatering system of claim 15 , wherein the water is brine.

17 . The dewatering system of claim 15 , wherein the at least one conduit is configured to fluidly couple to a water filter assembly on the terranean surface.

18 . The dewatering system of claim 17 , wherein the water filter assembly is a reverse osmosis filter assembly.

19 . The dewatering system of claim 15 , wherein the threshold level is at a predetermined depth below the terranean surface.

20 . The dewatering system of claim 15 , wherein the control system is configured to perform operations comprising:

periodically identifying the water level sensed by the water level sensor, and

when the water level does not exceed the threshold level, deactivating the subterranean pump.