已发表: 01/01/2019
已发表: 01/01/2019
With hundreds of thousands of well stages completed every year using the plug-and-perf (PNP) technique, it is the No. 1 stimulation process used in unconventional reservoirs. The inherent need for plug removal in a PNP operation has fueled the evolution of these devices to incorporate features to facilitate such removal. Early fracture plugs were made from metal and featured solid mandrels, making them extremely robust. As wells became longer and stage count higher, plug millout proved to be challenging. Under such conditions, returns do not easily reach the surface, and fluid is often lost into the recently created fractures. Debris from the plugs removed can accumulate in the horizontal section, posing a risk of getting the coiled tubing (CT) stuck during the operation.
As the industry demand for milling efficiency increased, plugs evolved to use softer materials. Plug mandrels moved toward composites and, similarly, slips moved to cast veneers and then to the various button materials currently in use. The latest efficiency improvement efforts focus on plug architecture, transitioning from topset designs to bottom-set designs. These designs eliminate the internal plug mandrel, which reduces the volume of material to mill and cleanout of the well. Combining this efficient design with advanced materials enabled the creation of the FracXion Micro fully composite fracture plug: short, strong and rapidly milled.
While the evolution of composite fracture plug technology has led to large efficiency improvements for multistage
Dissolvable technology delivers efficiency gains by optimizing the As the degradable technology adoption continues to grow, the operational experience has led to best practices that allow operators to eliminate the need for all mechanical intervention after stimulation. Modern “frac factory” pad operations typically use low-viscosity slickwater fluids, which can leave a large volume of proppant in the casing if not properly managed. Poor flowback practices can result in even more sand being pulled from near-wellbore fractures. Milling out conventional fracture plugs and removing the plug debris takes time and has an associated cost, but it has the added benefit of cleaning out the excess sand that would otherwise hinder production. Thus, to maximize efficiency when using dissolvable technology, it is critical to plan and manage proppant. Technologies, such as PropNET proppant flowback control technology and AvantGuard advanced flowback services, can help mitigate sand dune effects seen in these wells. Even with optimized operations and
For example, in a 3,048-m (10,000-ft) well with 46-m (150-ft) stage spacing, the engineers calculated that using degradable plugs in the last 1,524 m would save more than $22,000 as compared with using conventional fracture plugs for the whole well. Using a similar analytic approach, where individual well conditions are used to evaluate the cost of mechanical intervention, guidelines were developed for different well configurations and stage count.
As experience with hybrid
