Between a rock and a hard place: Fracking is the most efficient method for accessing deep reserves

The sultanate has a proven track record in the extraction of unconventional oil and gas. Its Block 61 project, undertaken with BP, is one of the most ambitious tight gas drilling projects in the world and, in the view of many in the industry, the technology employed there represents the future of gas production in the sultanate. “In Oman, because of its hydrocarbons clusters, the tight nature of the oil, fracturing makes wells cost effective. All of the gas comes from fracking, and some of the oil – it grew rapidly over the past two years and there will be more of it in the future,” Chokri Ben Amor, the general manager of Shlumberger Oman, told OBG.

The Process

Hydraulic fracturing, or fracking, in which fluid is injected into boreholes at high pressures in order to fracture shale rocks to allow for the release of natural gas, offers obvious advantages for Oman, and include improved recovery rates from the nation’s notoriously challenging fields; less dependence on foreign energy sources; and, in the case of natural gas, a more bountiful supply of one of the cleaner fossil fuels, which emits about half the amount of carbon dioxide as coal or oil. Additionally, some say methods could be advanced further if there was more investment in the technology. “Extraction could become much more efficient with only a marginal investment in capital,” N. Ramesh, the CEO of well-engineering services provider Abraj Energy Services, told OBG.

Potential Risks

There are, however, risks associated with the practice, and the concerns of increasingly vocal environmental lobbyists, particularly those of the UK and US, are well known: the possibility of methane gas and toxic chemicals leaking from wells and contaminating nearby groundwater; the 30-50% of fracking fluid left in the ground that in some cases is not biodegradable; and the deposits of waste fluid that are left on the surface, where potentially harmful volatile organic compounds are released into the air. Much of what is asserted with regard to fracking is disputed by the oil and gas industry, which has launched numerous initiatives to combat the perception that fracking is a dangerous activity. For example, FracFocus is an online chemical disclosure registry where visitors can see what substances are being explored in fracking fluids used in participating wells.

Engineering Solutions

But where there is a clear environmental risk, the industry has sought solutions that satisfy environmental concerns without eroding the financial viability of well development. One of the most innovative of these is based at Oman’s Nimr oil field. Operated by Petroleum Development Oman (PDO), the site produces around 250,000 cu metres of contaminated water per day, together with the oil that is brought to the surface. Only one-tenth of the liquid that emerges from the wellbore is petroleum, and traditionally the unwanted by-product would be pumped back underground. However, since November 2010, wastewater produced by the Nimr operation has been flowing into the world’s biggest commercial reed-bed treatment plant, which covers an area of 235 ha. The plant-based, eco-friendly water system is the work of Germany-based Bauer Group, and is groundbreaking in terms of the process of water management.

An initial pilot project showed that locally sourced reeds were capable of surviving exposure to the toxic wastewater almost undamaged, and a four-stage purification system has been devised that removes the impurities left after the oil has been separated. By adopting the reed-bed process on a large scale, PDO has brought new efficiencies to Nimr: the plant is currently purifying around 47,000 cu metres of contaminated water a day and attaining a purification level of 99.5%. According to Bauer Group, crude oil to the value of several thousand dollars is recovered from the system daily, and the plant’s energy requirements have been reduced by more than 80% in comparison to standard processes. Moreover, by-products produced by the purification process, such as salt and biomass, also hold potential value which, taken with the other efficiencies, demonstrates that environmental protection does not always come with increased costs.