Getting Into Hot Water: An Opportunity For The Petroleum Industry

Abstract

There are around 700 new geothermal power projects in 76 countries according to the 2016 Annual Report of the Geothermal Energy Association. Growth of the market is around 5% annually and current installed capacity of about 12,500 megawatts. The forecast for 2021 is around 18,400 megawatts. These figures are impressive, but they do not bear comparison with any of the fossil fuels. Such a statement will surprise no one, but few will realise that the global oil industry (as opposed to that for gas or coal) has a cryptic geothermal power potential that is, perhaps, equal to the entire current output of the geothermal industry and the usable thermal output from the same sources substantially higher. The oil industry is ageing. Production from many provinces has reached or even surpassed middle age. This is the case for much of the Middle East, the Caspian region, Alaskan North Slope, the North Sea and adjacent areas, Venezuela, Mexico, Indonesia, North Africa and parts of West Africa. It is true that these areas still produce copious quantities of oil, but the oil comes with an unwanted by-product - water. Indeed, for most areas, the current production is probably best described as water production with a valuable by-product of oil. The volume of water produced is typically is ten to twenty times that of the oil (Figure 1); and the water is hot - in some places very hot (>100°C). In a recent study (Auld et al, 2014) we have shown that the power depleted oil production platforms of the North Sea’s North Viking Graben produce sufficient hot water to deliver around 60% of the power requirement for each field. In another study we have demonstrated that the discarded heat from co-produced water in a UK onshore field is some 40x greater than that delivered from an adjacent dedicated geothermal project. The geothermal heat from co-produced water in oilfield operations is free and derivative electrical power produced using Organic Rankine or similar systems would be low cost. An additional benefit from either heat use or power generation from such systems is that the re-injected waste (now) cold water has better sweep efficiency for additional oil recovery. A review of global oil and hence water production has enabled us to calculate that power production alone from waste water from producing oilfields could be at least 15,000 megawatts.

AAPG Datapages/Search and Discovery Article #90345 © 2018 AAPG European Region, Geothermal Cross Over Technology Workshop, Part II, Utrecht, The Netherlands, April 17-18, 2018