Waffle well pattern with networked wells for hydrocarbon recovery and related methods

Abstract

The present description relates to a waffle well process and system that includes a multileg horizontal well and a crossover well that can be a fishbone or feather well, for example, where lateral well sections crossover and intersect to provide a network for hydrocarbon recovery.

1 . A method for recovering hydrocarbons from a subterranean reservoir comprising:
 providing a multileg horizontal well in the reservoir, the multileg horizontal well comprising a vertical well section and multiple horizontal legs extending from the vertical well section;   providing a crossover well in the reservoir, the crossover well sharing at least a portion of the vertical well section of the multileg horizontal well and comprising a spine well section and rib well sections extending from the spine well section, wherein a plurality of the rib well sections intersect with a plurality of the multiple horizontal legs to form a waffle well network; and   producing hydrocarbons that flow through the waffle well network for recovery at surface.   
     
     
         2 . The method of  claim 1 , further comprising a pre-treatment stage where a treatment fluid is injected or circulated into the waffle well network prior to the step of producing. 
     
     
         3 . The method of  claim 2 , wherein the pre-treatment fluid comprises steam, acid, hot water, surfactant, or a combination thereof. 
     
     
         4 . The method of  claim 1 , wherein the horizontal legs and the rib well sections are aligned in a same plane within the reservoir within 1 meter of each other at intersections thereof. 
     
     
         5 . The method of  claim 1 , wherein intersections of the rib well sections and the leg well sections include partial intersections, full intersections, and/or spaced-apart intersections with fluid communication between the corresponding well sections. 
     
     
         6 . The method of  claim 1 , wherein at least 50% of the crossovers between rib well sections and leg well sections provide respective intersections. 
     
     
         7 . The method of  claim 1 , wherein the rib well sections extend at a forward angle from the spine well section, wherein the forward angle is between 20 and 70 degrees. 
     
     
         8 . The method of  claim 1 , wherein the rib well sections each have a substantially same length, wherein the rib well sections are each generally straight, and wherein the rib well sections are evenly spaced apart from each other along the spine well section. 
     
     
         9 . The method of  claim 1 , wherein at least some of the rib well sections intersect with respective multiple leg well sections, or wherein at least some of the leg well sections are intersected by multiple rib well sections. 
     
     
         10 . The method of  claim 1 , wherein the rib well sections extend from both sides of the spine well section such that the crossover well is a fishbone well. 
     
     
         11 . The method of  claim 1 , wherein the rib well sections extend from one side of the spine well section such that the crossover well is a feather well, where the spine well section is a shaft well section and the rib well sections are barb well sections. 
     
     
         12 . The method of  claim 1 , wherein a tertiary well is provided and intersects with rib well sections and leg well sections. 
     
     
         13 . The method of  claim 1 , further comprising completing at least one of the rib well sections with a liner prior to producing. 
     
     
         14 . A method for recovering hydrocarbons from a subterranean reservoir comprising:
 providing a multileg horizontal well in the reservoir, the multileg horizontal well comprising a vertical well section and multiple horizontal legs extending from the vertical well section;   providing a crossover well in the reservoir, the crossover well comprising a spine well section and rib well sections extending from the spine well section, wherein a plurality of the rib well sections intersect with a plurality of the multiple horizontal legs to form a waffle well network; and   producing hydrocarbons that flow through the waffle well network for recovery at surface.   
     
     
         15 . The method of  claim 14 , wherein the crossover well comprises a crossover vertical well section coupled to the spine well section. 
     
     
         16 . The method of  claim 14 , wherein the crossover vertical well section is distinct form the vertical well section of the multileg horizontal well. 
     
     
         17 . A method for recovering hydrocarbons from a subterranean reservoir comprising:
 providing a multileg horizontal well in the reservoir, the multileg horizontal well comprising a vertical well section and multiple horizontal legs extending from the vertical well section;   providing a crossover well in the reservoir, the crossover well sharing at least a portion of the vertical well section of the multileg horizontal well and having a horizontal well section extending across and in spaced-apart relation to a plurality of the horizontal legs;   performing a fracturing operation in the crossover well to form fractures that extend from the crossover well to at least some of the horizontal legs, thereby forming an interconnected well network;   producing hydrocarbons that flow through the interconnected well network for recovery at surface.   
     
     
         18 . The method of  claim 17 , wherein the crossover well is located above the legs by a vertical offset distance up to two meters. 
     
     
         19 . The method of  claim 17 , wherein the crossover well extends diagonally across the legs. 
     
     
         20 . The method of  claim 17 , wherein the fracturing operation is performed using multistage fracturing.