Simulation Study Investigating the Impact of Carbon Dioxide Foam Fracturing Fluids on Proppant Transport

Abstract

Production from unconventional reservoirs using hydraulic fractured wells has recently gained much attention due to its ability to increase recovery to high percentages. The placement of proppant in fractures plays a significant role in conductivity of fractures and well productivity. Here, we aimed to elucidate some basic concepts of the technique using FracPro simulator. FracPro and hydraulic fracturing consist of many design parameters that effect the results of the stimulation process. Of the many parameters that exist, three were focused on in this paper: proppant transport, the use of carbon dioxide (CO2) foam fracturing fluid, and the use of low specific weight versus higher specific weight. FracPro was also used to simulate the results of using a low specific gravity value of 1.9, a medium value of 2.7, and a high value of 3.5. The concentration of CO2 was also varied in each condition; concentrations of 30, 50, and 70% were used. After running investigating these scenarios, some unexpected results were obtained. Notably, a lower specific gravity should produce a longer effective proppant length; however, our data indicates shows the opposite.

Asphaltene Precipitation and Deposition during Nitrogen Gas Cyclic Miscible and Immiscible Injection in Eagle Ford Shale and Its Impact on Oil Recovery

“…Unconventional resources, like shale reservoirs, are widely recognized for their extremely low permeability and porosity . Despite the fact that multistage hydraulic fracturing and horizontal well drilling techniques are used to extract the remaining oil from such reservoirs, only 4–6% of the trapped oil can be extracted, and the oil production drops after a few months, attributing to the ultralow permeability. − Water injection is also one of the suitable strategies for increasing oil recovery from conventional reservoirs; nevertheless, due to weak injectivity, insufficient sweep potency, and clay swelling concerns, this approach is not the ideal solution for tight reservoirs. , Cyclic gas injection outperforms gas flooding methods in terms of enhancing oil recovery, mainly in ultratight reservoirs. , The total organic carbon (TOC) is the most important influencing parameter on gas injection in tight reservoirs because kerogen makes the surface of the pore oil-wet, making the oil inside challenging to extract . Due to the combination of multiphase fluids (i.e., gas, oil, condensate, and water) and scales, multiphase flow production can create a number of challenges including wax and asphaltene deposition, hydrate formation, slugging, and emulsions .…”

Co-Injection of Foam and Particles: An Approach for Bottom Water Control in Fractured-Vuggy Reservoirs

“…Not only does this leverage the advantages of solid-phase particles with high-pressure resistance, strength, and strong shear force resistance, but it also effectively improves the ability of particles to pass through the formation under the influence of the reservoir. This achieves the goal of "plugging high permeability areas and driving the low permeability areas" [28][29][30][31]. This provides an approach for the efficient development of fractured-vuggy reservoirs: the simultaneous injection of foam and solid particles.…”

Experimental Investigation of Asphaltene Deposition and Its Impact on Oil Recovery in Eagle Ford Shale during Miscible and Immiscible CO2 Huff-n-Puff Gas Injection

“…Unconventional resources, such as shale reservoirs, are well-known to have ultra-small permeability and very low porosity . Only 4–6% of the trapped oil may be retrieved using multi-stage hydraulic fracturing and horizontal well drilling methods, − and oil production decreases after months attributable to the ultra-small permeability of such reservoirs. − The water flooding technique is one applicable method that can increase oil recovery (OR) from conventional reservoirs; however, this technique is not the optimal choice for tight reservoirs due to their poor injectivity, poor sweep potency, and clay swelling issues. , Gas injection has become a widespread technology that improves oil production in unconventional reservoirs in the United States and could be the best reliable method to unlock the remaining oil percentage . Huff-n-puff gas injection has a more advantageous impact in increasing OR compared to gas flooding techniques, especially in ultra-tight reservoirs with the matrix permeability under 0.001 mD. , Because kerogen renders the surface of the pores oil-wet, extracting the oil from inside tight reservoirs is restricted by the presence of a high total organic carbon (TOC) .…”