System and method for accessing subterranean deposits
According to one embodiment, a system for accessing a subterranean zone from the surface includes a well bore extending from the surface to the subterranean zone, and a well bore pattern connected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.
1. A system for accessing one or more subterranean zones, the system comprising:
a drilling pad at a land surface;
a first well, located on the drilling pad, comprising a substantially vertical wellbore coupled to a first junction proximate a subterranean zone, a first horizontal drainage wellbore extending from the first junction with a horizontal portion that extends at least 2,440 feet;
a second well, located on the drilling pad, comprising a substantially vertical wellbore coupled to a second junction proximate the subterranean zone, a second horizontal drainage wellbore extending from the second junction with a horizontal portion that extends at least 2,440 feet;
wherein the wells are offset from each other by 2-100 feet at the surface;
wherein the first well horizontally extends into the subterranean zone in a first direction;
wherein the second well horizontally extends into the subterranean zone in a second direction;
wherein a drilling pad surface area is smaller than an area containing the first and second horizontal drainage wellbores;
wherein the subterranean zone is a low porosity zone; and
wherein both the first and second wells are cased at least in the substantially vertical wellbores and are configured to produce fluids to the surface.
2. The system of claim 1 wherein at least one drainage wellbore extends into a second subterranean zone creating a multi-level drainage pattern that is rectangular in area with a length of 6,980 feet or more, and where the at least one drainage wellbore has a length extending into the second subterranean zone of at least 6,980 feet.
3. The system of claim 1 wherein the first and second wells form a drainage pattern that is substantially rectangular and where the length of the horizontal drainage wellbores of each well is at least 6,980 feet.
4. The system of claim 1 wherein there are 5 or more cavities caused by fracing in the first and second horizontal drainage wellbores and wherein the first and second horizontal drainage wellbores are configured to produce a fluid, selected from a group consisting of oil, gas, water, and combinations of the above-listed elements, to the surface;
wherein water and other additives are injected into the first and second horizontal drainage wellbores from the surface; and
wherein the first and second wells create a drainage pattern that is rectangular in area;
wherein each horizontal drainage wellbore has a length of at least 6,980 feet.
5. The system of claim 1 further comprising:
a pump, selected from a group consisting of an electrical submersible pump and a progressing cavity pump, disposed within one of the horizontal drainage wellbores; and
wherein the first and second wells are cased.
6. The system of claim 1 wherein the substantially vertical wellbore of the first well is drilled first, the substantially vertical wellbore of the second well is drilled second, and the horizontal drainage wellbores of each well are drilled thereafter.