Channel Fracturing
new tech
Unconventional Resources C hannel Fracturing Schlumberger’s stimulation technology aims for higher production and recovery rates
In the fiercely com- technology, according to Peña. proppant pulses cohesive, with the right pulse duration and petitive world of unconventional These include a specialized preventing them from spread- with the right proppant concen- oil and natural gas production, pumping technique, advanced ing as they travel through the tration to deliver open channels. operators are constantly on the fibre technology, completion surface lines and down into the The most important aspects lookout for any new technolo- strategy (placement of perfora- completion. The fibre also helps of the technique are modelling gies that can help to provide tions) and engineering modelling. to improve the carrying and engineering, says Peña. that extra edge. Schlumberger uses its capacity of the fluid-proppant- A geomechanical model was Among those technologies is specialized blending equipment fibre mixture, making it easier developed specifically for the Schlumberger’s new HiWAY and control systems to pump for the fluid to transport the application and is now incorpo- flow-channel hydraulic proppant in pulses at a high proppant pulses. Thirdly, the rated in Schlumberger's fracturing technique, which frequency within the fracture. fibre helps keep the pulses fracture design tools. The improves the ability of a fracture The proppants help hold the suspended within the fracture, proprietary Schlumberger to deliver increased oil and gas fracture open, servings as preventing them from settling FracCADE fracturing design production. “It’s a technique “columns” for the channels to while the fracture closes. and evaluation software is that changes radically the way in be developed around them. The engineering modelling currently the only design which we generate conductivity The fibre plays several roles, ensures that the HiWAY fluid is software in the industry that is within a hydraulic fracture,” including helping to keep the being pumped at the right rate able to predict the formation of says Alejandro Peña, worldwide well stimulation product champion for Schlumberger. The technique decouples fracture conductivity from proppant pack permeability by creating stable flow channels. Instead of flowing through the proppant pack, hydrocarbons flow through these channels, significantly increasing conductivity. The network of channels extends from the near-wellbore region to the tip of the fracture. It allows for longer effective fracture half-lengths, lower pressure drops along the fracture, and better fluid and polymer recovery, all of which contribute to optimized production and hydrocarbon recovery. Schlum- berger has seen a consistent trend across the board, with increases typically exceeding 25 per cent, says Peña. A number of related and interdependent elements contribute to the success of the
A better frac HiWAY flow-channel hydraulic fracturing technique shown on the right, as compared to conventional
fracturing on the left. Illustration: Schlumberger
New Technology Magazine | April 2011 43 new tech
channel fractures in the way that suitable for the HiWAY have been in United States Energy Corporation is one of it is done by HiWAY, he says. technique, there may be some Rockies and southwest Texas, the companies that last fall Schlumberger qualifies a cases in which the rock will not the technique also has been used implemented the technique on a reservoir for the use of the tech- be stiff enough to support a on jobs in Mexico, Argentina select number of wells as a trial nique. The company runs the network of open channels, and Russia. to determine the impact on reservoir properties through its according to Peña. In those Schlumberger has plans to horizontal multistage produc- software tool, generating a cases, the engineering tools will introduce HiWAY into Western tion in the Eagle Ford shale. fracturing proposal that tells provide the necessary warnings. Canada this year and currently Initial production results from the customer whether it should HiWAY has been used with is evaluating several candidate the limited set of wells in the success in both oil and gas res- formations. Hawkville field reflect average ervoirs with a wide range of In addition to increased production increases of lithologies including carbonates, production, the HiWAY approximately 37 per cent in the sandstones, shale/carbonate technology offers a more reliable areas with gas and natural gas mixtures and shale/sandstone placement of fracturing materials, liquids and an average of mixed formations. It also has according to Peña. “It provides approximately 32 per cent in the been pumped with temperatures customers with the confidence high condensate yield areas, the ranging from 140 F to 325 F. that they will be able to place the company reported. The project was launched in job as designed,” he says. Based on internal estimates 2003, with the first field testing So far there have been no for the limited trial, Petrohawk in 2007. “All those years were reports of “screenouts” due to says that the estimated ultimate devoted to developing the engi- this technique, in which the recovery increased by between neering principles and the tech- stimulation ends prematurely 25 per cent and 90 per cent expect to generate channels nology that allow us to deliver because the formation can no compared to offsetting wells within the fracture and what the HiWAY service,” says Peña. longer take in any more fluid. completed with conventional kind of conductivity those HiWAY was commercialized The operator typically ends up fracturing techniques. The channels would generate. last June and “the take-up of the with a wellbore full of proppant company says it has converted The key in determining technology has been impres- and fluid that needs to be 100 per cent of the frac services reservoir suitability for the sive,” he says, with 520 of the cleaned out before the well can provided by Schlumberger in technique is rock competency. total 550 jobs taking place since be put on production. the Eagle Ford to HiWAY. •
Photo: Schlumberger Although most reservoirs are then. Although most of the jobs Houston-based Petrohawk Elsie Ross
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