【系列专题】页岩油的创新时代：生产回忆录（1）

PROPPANT TECH ENHANCES WATER SOURCE FOR FRACTURING COMPATIBILITY

Expansion in hydraulic fracturing has created an industrywide water management concern, both in the sourcing of freshwater and produced water disposal. The growth of stimulation programs is putting oil and gas in competition for potable water with other industries and municipalities. A formulation of self-suspending proppant (SSP) approaches this challenge by correcting the water source to make it compatible with fracturing fluid systems. This SSP technology serves as a proppant coating that adapts to produced water with minimal to no pretreatment. It also relies on a hydrogel coating atop raw sand or ceramics that hydrates in water with measured total dissolved solids up to 350,000 parts per million (ppm) and hardness up to 40,000 ppm. The hydrated coating reduces the effective density of the proppant, decreasing proppant settling and creating greater stacked height of the proppant in the fracture. Since the coating is bonded to the individual proppant particle and does not crosslink or significantly viscosify the carrying fluid, the resulting fracture fluid system exhibits exceptionally low frictional pressure even at high proppant loading rates. This technology allows an operator to pump a slickwater-like fracture program with low-quality water while still achieving proppant loading rates that can range from 0.25 pound of proppant added (ppa) to 12 ppa—all without damaging the formation or proppant pack itself. Propel SSP couples improved proppant transport to environmental stewardship, allowing companies to mitigate risks to their operation while simultaneously building better wells.

RESIN-COATED PROPPANTS INCREASE LONG-TERM PRODUCTION

O’s advanced resin-coated proppant technology helps operators improve their well economics. Most completed wells use uncoated fracturing sand—often regardless of the downhole conditions—in an effort to reduce cost. The IPs of these wells look very promising. However, as the uncoated fracturing sands are continuously subjected to downhole pressure, temperature and moisture, they might begin to crush. This can impact fracture conductivity within the first few months. Uncoated fracture sand is less expensive initially compared to resin-coated sand. However, once these proppants begin to fail, well production begins to decline. Resin-coated proppants have been found to withstand downhole conditions such as high-closure stress and cyclic stress changes, resulting in improved long-term hydrocarbon production. Production data studies continue to prove that uncoated fracturing sand, particularly in deeper wells, leads to production declines far steeper than resin-coated proppants. A recent example is in the Permian Basin, where offset wells were used with similar conditions. O’s P proppants outperformed uncoated fracturing sand with a 49% increase in production over 12 months.

PROPPANT HELPS REDUCE FLOWBACK AND IMPROVES CONDUCTIVITY

For pressure pumping and E&P companies working in the Permian Basin and other shale plays, one goal is to get more out of the well while putting less into it in terms of time, money and potentially hazardous chemicals. In low-temperature reservoirs, however, liquid chemical activators are typically added to bond resin-coated sand together, a process that increases expense and risk. U.S. S’s new proppant, L, was created to eliminate the need for activators as well as the cost, safety and environmental concerns that accompany them. The formaldehyde-free resin-coated proppant outperforms all competitive products designed for low-temperature reservoirs. Because of its bond strength, L can significantly reduce or prevent flowback at downhole temperatures as low as 21 C (70 F) without requiring an activator. In addition, independent tests indicate L delivers best-in-class crush resistance and hydraulic conductivity. Crush resistance keeps fractures from closing and prevents fines that can reduce flow. Superior conductivity means the proppant brings hydrocarbons to the surface faster for better return on investment and lower overall cost. To ensure consistent quality, L’s substrate is U.S. S White sand. The product is available in multiple mesh sizes and is compatible with all current fluid systems.