To the casual observer of completions and hydraulic fracturing, it might appear that multifractured horizontal wells are a relatively recent concept that materialized just as we required them for unconventionals. However, those in the know will recognize that the marriage of fracturing and stimulation operations with horizontals was forged almost 30 years ago in an environment far removed from unconventionals.
Among the top 10 largest discoveries in 2013, half of them are natural-gas discoveries and all of them are in offshore environments, primarily in Africa, Far East Asia, and transcontinental countries, with estimated resources of more than 4,000 million BOE. To bring gas from remote locations to the markets will remain an imposing task, with unavoidable challenges in terms of exploration, production, processing, and transportation, especially now when both oil and gas prices are low.
Technologies in our industry are constantly advancing from more-thorough consideration for improving designs and from findings that emerge from focused research-and-development activities. HP/HT design and operations are key areas where the most-sophisticated engineering methods are warranted. These important and innovative industry advancements are driven by the unchanging principles of ensuring fit-for-purpose, safe, and reliable HP/HT well designs and operations.
Nowadays, there is a wealth of history-matching methods. As a result, we observe that it is becoming a common industrial practice to generate multiple history-matched models, even for fairly complex problems with thousands of uncertainty variables and a large amount of data. However, we are still far from a definitive solution. Actually, it seems that there will be no single best history-matching technique. Instead, what we may have is the best method for the specific problem.