Liner hanger system

1. A system comprising:

a casing for lining a wellbore;

a collar configured for connection to a part of the casing within the wellbore, the collar having a first shape;

a liner hanger having a second shape that is based on the first shape, the liner hanger being configured to fit within, and to be supported by, the collar;

a screen connected to the liner hanger;

a setting tool configured to connect to the liner hanger to attach the liner hanger to the collar, the setting tool comprising a pipe that is runnable downhole within the wellbore, the setting tool being configured to connect to the liner hanger using a J-slot mechanism, where the J-slot mechanism comprises two J-slot structures configured to oppose each other on an inner profile of the liner hanger; and

an anchor that is extendible from opposing sides of a shaft of the setting tool, the anchor being configured to engage the two J-slot structures.

2. The system of claim 1 , where the first shape comprises a cylindrical shape that tapers from top to bottom; and

where the second shape comprises a cylindrical shape that tapers from top to bottom.

3. The system of claim 1 , where the first shape is at an interior profile of the collar and comprises a cylindrical shape that tapers from top to bottom; and

where the second shape is at an exterior profile of the liner hanger and comprises a cylindrical shape that tapers from top to bottom.

4. The system of claim 1 , where the wellbore is for a vertical water well; and

where the screen is configured to allow water to pass through the screen but to prevent at least some particulate matter from passing through the screen.

5. The system of claim 1 , where the screen has first threads and the liner hanger has second threads, the second threads being complementary to the first threads.

6. The system of claim 1 , where the liner hanger is not cemented within the wellbore.

7. The system of claim 1 , where the screen comprises a shoe that extends to a completion zone of the wellbore.

8. The system of claim 1 , further comprising a liner top packer that seals at least a portion of the casing to an adjacent casing,

where the casing and the adjacent casing form a casing string.

9. The system of claim 8 , where the liner top packer forms a seal between the casing and the adjacent casing using an elastomeric material on an outer surface of the liner top packer.

10. The system of claim 9 , where the casing comprises a first casing,

where the system comprises a second casing comprising an outer diameter,

where the outer diameter of the second casing is configured to fit within an inner diameter of the first casing, the first casing and second casing forming a casing string.

11. The system of claim 8 , where the liner top packer comprises a sealing sleeve that expands when placed within the casing string, and

where the casing string comprises an outer diameter of 9⅝ inches and an inner diameter of 8½ inches.

12. A method comprising:

attaching a screen to a liner hanger;

connecting a setting tool to the liner hanger having the screen attached;

running the setting tool connected to the liner hanger into a wellbore, the setting tool being run in the wellbore to a point proximate to an end of a casing lining the wellbore, the casing comprising a collar located proximate to the end of the casing;

securing the liner hanger to the collar; and

after the securing, releasing the setting tool from the liner hanger,

where the setting tool is configured to connect to the liner hanger using a J-slot mechanism;

where the J-slot mechanism comprises two J-slot structures opposing each other on an inner profile of the liner hanger;

where the casing comprises a liner top packer that seals at least a portion of the casing to an adjacent casing, and

where the casing and the adjacent casing form a casing string.