Hydraulic Fracturing with Dissolvable Fracture Plugs
Hydraulic fracturing is a well-stimulation technique used commonly in low-permeability rocks and benefits greatly by using dissolvable fracture plugs.
Hydraulic fracturing is a well-stimulation technique used commonly in low-permeability rocks like tight sandstone, shale, and some coal beds to increase oil and/or gas flow to a well from petroleum-bearing rock formations. A similar technique is used to create improved permeability in underground geothermal reservoirs. It involves blasting fluid deep below the earth’s surface to crack sedimentary rock formations—this includes shale, sandstone, limestone, and carbonite—to unlock natural gas and crude oil reserves. One method of hydraulic fracturing uses only dissolvable fracture plugs in the wellbore.
The process begins with the drilling of a long vertical or angled well that can extend a mile or more into the earth. As the well nears the rock formation where the natural gas or oil lies, drilling then gradually turns horizontal and extends as far as thousands of feet. Steel pipes called casings are inserted into the well, and the space between the rock and the casing is fully or partially filled with cement. Small holes are made in the casing with a perforating gun, or the well is constructed with pre-perforated pipe. Fracking fluid is then pumped in at a pressure high enough to create new fractures or open existing ones in the surrounding rock. This allows the oil or gas to flow to the surface for gathering, processing, and transportation, along with contaminated wastewater that is stored in pits and tanks or disposed of in underground wells. Part of the facing process requires frac plugs as part of the Plug-and-perf operation. Plug and perf can use dissolvable fracture plugs in the wellbore to save money and reduce the milling process.
Plug-and-perf includes pumping down a bridge dissolvable fracture plugs in the wellbore on wireline with perforating guns to a given horizontal location near the toe of the well. The dissolvable fracture plugs is set, and the zone is perforated. … The stage is completed, the next dissolvable fracture plugs and perforations are initiated, and the process is repeated moving back to the heel of the well. In a plug-and-perf operation, a plug and perforating guns are pumped to the appropriate depth. … A ball is pumped down to isolate the zones below the plug, and the fracture stimulation treatment is pumped. The ball-activated plug diverts fracture fluids through the perforations into the formation.
Permian Basin in Texas and New Mexico is currently the epicenter of this global surge of oil and gas production and Hydraulic fracturing and the use of dissolvable fracture plugs. No other geological basin has so much potential for production growth. Projections suggest that oil production, including production of fossil gas liquids (hydrocarbons such as ethane, propane, and butane, used for heating and cooking and as feedstock for the petrochemical and plastics industry) could grow from 4.7 million barrels per day to nearly 12 million barrels per day by 2030. The largest Operators in the Permian Basin include Diamondback Energy, XTO Energy, Pioneer Resources, OXY and Devon Energy.
One example is Diamondback Energy, Inc. is an independent oil and natural gas company currently focused on the acquisition, development, exploration and exploitation of unconventional, onshore oil and natural gas reserves in the Permian Basin in West Texas. A typical horizontal Permian Basin Wolfcamp well is completed for $6.8 million, with 30 frac stages using a slickwater stimulation technique and is currently producing with an electric submersible pump. Horizontal wells commonly have 30-40 frac stages now rising lateral lengths, more stages are required to ensure effective stimulation occurs. Slickwater fracs utilize extremely high volumes of water but minimize frac fluid chemical additives. This is an ideal situation for the use of dissolvable fracture plugs to save money and bring production of the well sooner.