Pad site construction and method

1. A method for supporting an oilfield rig structure, comprising:

positioning a plurality of piles in a ground of a core operating section of a pad site;

laying a plurality of mats over the pad site, wherein a first portion of the plurality of mats are at least partially supported by the plurality of piles, and a second portion of the plurality of mats are not supported by the plurality of piles, and wherein the first portion of the plurality of mats are configured to support an oilfield rig structure; and

spreading a layer of gravel over the first portion of the plurality of mats.

2. The method of claim 1 , further comprising determining a torque, a depth, or both for positioning the plurality of piles based on one or more characteristics of the ground and one or more characteristics of the oilfield rig structure, wherein positioning the plurality of piles comprises drilling the plurality of piles into the ground at the determined torque, depth, or both.

3. The method of claim 1 , further comprising spreading the layer of gravel over the second portion of the plurality of mats.

4. The method of claim 1 , further comprising adjusting a height of at least one of the plurality of piles after drilling the at least one of the plurality of piles into the ground.

5. The method of claim 1 , further comprising:

supporting the oilfield rig structure on the first portion of the plurality of mats at the core operating section of the pad site;

drilling a wellbore using the oilfield rig structure while the oilfield rig structure is supported on the first portion of the plurality of mats;

moving the oilfield rig structure on the first portion of the plurality of mats; and

drilling a second wellbore using the oilfield rig structure after moving the rig structure.

6. The method of claim 1 , further comprising digging one or more trenches in the ground prior to laying at least some of the plurality of mats over the pad site.

7. The method of claim 1 , further comprising:

removing at least some of the plurality of mats;

removing at least some of the plurality of piles; and

re-using the at least some of the plurality of mats and the at least some of the plurality of piles.

8. The method of claim 1 , wherein the plurality of mats each include corners, wherein laying the mats comprises laying the first portion of the plurality of mats such that the corners thereof are each on top of one of the plurality of piles.

9. The method of claim 1 , wherein the second portion of the plurality of mats are configured to support auxiliary structures.

10. The method of claim 1 , wherein at least one of the piles is configured to support corners of four of the plurality of mats.

11. A pad site comprising:

a core operating section;

a secondary section defined adjacent to at least a portion of the core operating section;

a plurality of piles installed into a ground, wherein the plurality of piles are distributed in the core operating section;

a first plurality of mats positioned at the core operating section, each of the first plurality of mats comprising corners, the corners each being position on top of one of the plurality of piles;

a second plurality of mats that do not engage the plurality of piles and are not positioned over the core operating section of the pad site, the second plurality of mats being positioned over the secondary section; and

a layer of gravel positioned over the first plurality of mats.

12. The pad site of claim 11 , wherein each of the first plurality of mats and each of the second plurality of mats are made from concrete.

13. The pad site of claim 11 , wherein the layer of gravel is positioned over the second plurality of mats.

14. The pad site of claim 11 , further comprising one or more trenches in the ground below the first plurality of mats, below the second plurality of mats, or both.

15. The pad site of claim 11 , wherein the plurality of piles are helical piles, the helical piles being torqued to a predetermined torque load and installed to a predetermined depth.

16. The pad site of claim 15 , wherein the helical piles have an adjustable height, to level the first plurality of mats.

17. The pad site of claim 15 , further comprising an oilfield drilling rig that is movable on the first plurality of mats and is supported by the first plurality of mats and the plurality of piles.

18. The pad site of claim 11 , wherein at least some of the first plurality of mats, at least some of the second plurality of mats, and at least some of the plurality of piles are removable for re-use at another pad site.

19. A method of supporting an oilfield drilling rig, the method comprising:

excavating a layer of ground to form a pad site;

digging one or more trenches in the pad site;

determining a depth, torque, or both for a plurality of helical piles to be installed at the pad site based on one or more characteristics of the ground, one or more characteristics of the plurality of helical piles, and one or more characteristics of the drilling rig to be supported;

installing a plurality of helical piles at the determined depth, the determined torque, or both at a core operating section of the pad site;

positioning a plurality of mats on the pad site, wherein a first portion of the plurality of mats are positioned at the core operating section and are at least partially supported by the plurality of helical piles, and wherein a second portion of the plurality of mats are positioned on a secondary section of the pad site and are not supported by the plurality of helical piles; and

laying a layer of gravel over the first portion of the plurality of mats.

20. The method of claim 19 , further comprising:

positioning an oilfield rig at a first well site of the core operating section of the pad site, wherein the oilfield drilling rig positioning at the core operating section is supported by at least one of the first portion of the plurality of mats and at least one of the plurality of helical piles;

drilling a first wellbore in the ground at the first well site;

moving the oilfield drilling rig on the core operating section to a second well site, the oilfield drilling rig being supported by at least one of the first portion of the plurality of mats and at least one of the plurality of helical piles while moving the oilfield drilling rig; and

drilling a second well at the second well site.

21. The method of claim 19 , further comprising:

removing the layer of gravel;

removing at least some of the plurality of mats and at least some of the plurality of helical piles; and

re-using the at least some of the plurality of mats and the at least some of the plurality of helical piles in another pad site.

22. The method of claim 19 , wherein:

the one or more characteristics of the ground comprise rock content or soil content;

the one or more characteristics of the plurality of helical piles comprise a geometry of the plurality of helical piles; and

the one or more characteristics of the oilfield drilling rig comprises a weight of the oilfield drilling rig.