On August 29th, 2014, Jereh operated its CO2 fracturing in Jilin, China to have a region of production potential increase with over 15,538 cbft liquefied CO2 and 370 cbft proppant injection at 9,425psi working pressure, which leads to the largest CO2 fracturing operation in China.
Jereh integrated CO2 fracturing solution deployed one large volume closed-loop sand blender, continuous sand conveying system, eight 2000hhp truck mounted fracturing units and one data van. Jereh’s patented sand blender with vertical silo has greater sand storage capacity, which ensures smaller evaporation in the pre-coolling process in comparison with common horizontal sand blender. Double helix proppant conveyer can be standby for each other, meeting the requirements of large-scale continuous fracturing operation.
Black + 79-31-45 well located in Songliao Basin, 163 Block. The low-energy reservoir contains oil of high viscosity and high freezing point, so CO2 was the best choice for fracturing as it can can carry high concentrations of proppant and can be vaporizes to a gas in the well to speed up the oil flow.
To guarantee reliable long-time working performance, Jereh initiated a demonstration program on August 25th and 28th with 5,297cbft (150m³) liquefied CO2, presetting discharge flowrate and output capacity. Onsite layout was also optimized——three boost pumpers centralized，20 silos radiated with frac pumpers placed on one side.
Safety always comes first. To prevent operator from suffocation by CO2, frostbite and noise damage, a contingency plan was involved in solution with Jereh automatic and visualized monitoring system is applied for real-time working data, pressure, temperature, and noxious gas monitoring.
“This successful operation strengthens our confidence in CO2 fracturing technology.” said Mr. Cui Rizhe, the chief engineer of Jereh R&D center. “Today, the whole industry is challenged with problems including limited water resources, reservoir pollution and well production decrease. These all indicate a transition to a more eco-friendly solution, so CO2 stimulation can be a trend, especially for Europe and America shale development.”
Firstly, CO2 fracturing enjoys significant environmental advantages. “Conventionally, at least 100,000 bbl of water would be consumed for only one water-based fracturing operation, while CO2 can be used instead of water to achieve completely water elimination.” said Mr. Cui. “Moreover, the energy provided by CO2 gasification helps the removal of all residual liquid left in the formation. When liquid CO2 vaporizes to a gas and flows from the reservoir, it leaves no liquid or chemical damage in the formation”
Then, CO2 fracturing owns remarkable stimulation effect. Generally, CO2 fracturing is regarded as high-cost operation. However, its stimulation effect is 5 or 6 times more than water-based fracturing and 4 times than foam nitrogen. For shale gas development, CO2 is more suitable as its adsorption capacity with shale is stronger than that of methane and can replace CH4 in the shale formation. “Highly production brings about great economic advantage. We believe CO2 fracturing will play a key role for shale commercialization in the future.” Said Cui.
“Jereh never stops CO2 fracturing R&D over the past decade. By mastering leading CO2 stimulation technology with our integrated equipment offering, Jereh is committed to the industrial technology revolution.” Said Mr. Cui.