Pad drilling method for drilling multiple wells and a multi-well pad system employing the same
A well pad having a plurality of wells is described. The well pad has two parallel rows or linear arrays of well pairs, mirrored to each other in both a W-E direction and a S-N direction orthogonal to the W-E direction. Each row of well pairs comprises an inner row of injection wells and an outer row of production wells. A plurality of wellhead connection modules and a piping module are deployed between the two rows of well pairs. Each wellhead connection module is connected to one, two three or four well pairs. The piping module connects the wellhead connection modules to a central processing facility.
1. A well pad system having a first axis and a second axis orthogonal to the first axis, the first and second axes defining a coordinate system having four quadrants and an origin at the intersection of the first and second axes, the system comprising:
a plurality of interconnected first wellhead connection modules arranged in a linear array along the first axis; and
in each of N of the four quadrants, N being an integer between 1 and 4, inclusive,
a plurality of first wellheads forming a first row of wellheads parallel to the first axis and spaced therefrom with a distance of a positive number Y/2; and
a plurality of second wellheads forming a second row of wellheads parallel to the first axis and spaced therefrom with a distance of a positive number Y/2+Z; wherein
the plurality of first and second wellheads are connected to the plurality of first well connection modules; and wherein
the first wellheads are offset laterally from the second wellheads such that each neighboring pair of first wellheads has a second wellhead therebetween, forming an acute-angled triangle, wherein each first wellhead connection module has a neighboring first wellhead located laterally on each side of the left-hand and right-hand sides thereof and connected thereto, and each two adjacent first wellhead connection modules have two first wellheads therebetween;
a second wellhead connection module centered at the origin, the second wellhead connection module aligning to the plurality of first wellhead connection modules and interconnected therewith;
two of third wellheads on a first side of the first axis forming a third row of wellheads parallel to the first axis and spaced therefrom, the two of third wellheads respectively on the first side of the second axis and an opposite second side of the second axis and connected to the second wellhead connection module; and
two of fourth wellheads on the first side of the first axis forming a fourth row of wellheads parallel to the first axis and spaced therefrom, the distance between the fourth row of wellheads and the first axis being greater than that between the third row of wellheads and the first axis, the two of fourth wellheads respectively on the first and second sides of the second axis and connected to the second wellhead connection module.
2. The well pad system of claim 1 further comprising:
two of fifth wellheads on a second side of the first axis opposite to the first side, the two of fifth wellheads forming a fifth row of wellheads parallel to the first axis and spaced therefrom, the two of fifth wellheads respectively on the first and second sides of the second axis and connected to the second wellhead connection module; and
two of sixth wellheads on the first side of the first axis forming a sixth row of wellheads parallel to the first axis and spaced therefrom, the distance between the sixth row of wellheads and the first axis being greater than that between the fifth row of wellheads and the first axis, the two of sixth wellheads respectively on the first and second sides of the second axis and connected to the second wellhead connection module.
3. The well pad system of claim 2 wherein in each of the N quadrants, each first wellhead is paired with an immediate neighboring second wellhead forming a well pair, the well pair forming a well pair vector from the first wellhead thereof to the second wellhead thereof, the projection of the well pair vector onto the first axis pointing away from the origin and the projection of the well pair vector onto the second axis also pointing away from the origin.
4. The well pad system of claim 1 wherein N is greater than 1; and wherein the Y/2 in a first one of the N quadrants is the same as the Y/2 in a second one of the N quadrants.
5. The well pad system of claim 4 wherein Y is a value between about 6 m and about 30 m, inclusive.
6. The well pad system of claim 4 wherein Y is a value between about 6 m and about 30 m, inclusive.
7. The well pad system of claim 1 wherein N is greater than 1; and wherein the distance between the first and second rows of wellheads is Z, and wherein the Z in a first one of the N quadrants is the same as the Z in a second one of the N quadrants.
8. The well pad system of claim 1 to wherein in each of the N quadrants, each pair of adjacent first wellheads connected to the same wellhead connection module are spaced by a first distance X1, and each pair of adjacent first wellheads connected to different wellhead connection modules are spaced by a second distance X2.
9. The well pad system of claim 8 wherein X1 is equal to X2.
10. The well pad system of claim 8 wherein X2 is smaller than X1.
11. The well pad system of claim 8 wherein either of X1 and X2 is a value between about 6 m and about 30 m, inclusive.
12. The well pad system of claim 8 wherein X1 is different than X2.
13. The well pad system of claim 8 wherein either of X1 and X2 is a value between about 6 m and about 30 m, inclusive.
14. The well pad system of claim 1 wherein N is greater than 1, and wherein, in each of the N quadrants, the distance along the first axis between each first wellhead and the neighboring second wellhead on the second-axis side thereof is D, and wherein D is a same value for all N quadrants.
15. The well pad system of claim 14 wherein D is a value between about 1 m and about 20 m, inclusive.
16. The well pad system of claim 14 wherein D is a value between about 1 m and about 15 m, inclusive.
17. The well pad system of claim 1 to wherein the well pad system is a Steam Assisted Gravity Drainage (SAGD) well pad system.
18. The well pad system of claim 1 wherein for each well pair in each of the N quadrants, the first wellhead thereof is an injection wellhead, and the second wellhead thereof is a production wellhead.
19. The well pad system of claim 1 wherein N is greater than 1; and wherein the Y/2 in a first one of the N quadrants is different than the Y/2 in a second one of the N quadrants.
20. The well pad system of claim 19 wherein Y is a value between about 6 m and about 30 m, inclusive.