据全球能源新闻网8月7日报道，根据雷斯塔能源（Rystad）分析显示，美国致密油运营商数月来一直在耗尽其已钻井但尚未完工的油井（DUC）库存，随着钻井反应的放缓，2021年6月，该国主要油区“活跃的”DUC数量骤降至2381口，为2013年以来的最低水平。
截止6月底，二叠纪、鹰福特（ Eagle Ford）、巴肯（Bakken）、尼奥布拉拉（Niobrara）和阿纳达科（Anadarko）地区的水平DUC总数下降到4,510口井。这意味着从2020年6月6340口井的峰值减少1800口，在过去12个月内每月平均消耗150口井。上一次库存规模达到这一水平是在2018年下半年。
然而，总数包括所谓的“废弃的”DUC，即24个多月前钻探且尚未完工的油井。根据经验证据表明，95%以上的钻井通常在头两年内完成，因此那些两年以上的井现在完成的概率很低。因此，包括“废弃的”DUC来衡量未来活动或预测产量往往更具投机性。
雷斯塔能源公司页岩研究负责人Artem Abramov表示，从剩余的“活跃”DUC数量来看，在2022年上半年之前，美国陆上工业对每桶 70-75 美元的WTI市场做出大量的石油供应反应几乎是不可能的。任何进一步的压裂增加，以及随后的油井完井，现在将要求生产商首先通过增加更多钻机来扩大钻探规模。
除阿纳达科地区外，所有主要含油盆地的活DUC均有所下降。截至6月底，二叠纪仅有约1550口水平活跃DUC，较去年同期的2470口下降了37%。由于自新冠疫情引发的衰退开始以来，二叠纪的钻机活动保持了更强劲的势头，但与所有其他盆地的情况一样，活跃的DUC库存总量并未恢复到2013年的水平。
目前二叠纪盆地活跃DUC库存水平与2019年第二和第三季度相当。其他主要含油盆地的情况则更令人吃惊。南德克萨斯的鹰福特和巴肯各只剩下300口活跃DUC。自2010年以来，这两项开创性的油气勘探从未达到如此高的水平。尼奥布拉拉地区的活跃DUC库存已降至310口，为2013年以来的最低水平。
根据按钻探年份或油井被钻探的年份划分的致密油DUC库存总量的细目，清楚地表明，截至今年6月， 2019 - 2020年的年份对压裂活动具有重要影响。虽然新的油井正在钻探，但2021年的新库存不足以抵消2021年之前年份的枯竭率。
在之前的几个月里，我们反复强调2019年第四季度和2020年前三个月这一时期是新冠疫情引起的低迷开始时异常高的DUC库存积累的关键因素。截止今年6月，这些井的84%已经完工。虽然仍略低于2016年第四季度-2017年第一季度和2017年第四季度-2018年第一季度14个月创纪录的枯竭率(92-93%)，但与2018年第四季度-2019年第一季度和2019年4月至2020年6月期间的87%相当。
尽管仍存在一定程度的异常，但该行业距离 DUC库存水平完全正常化并不遥远。截至2021年6月，在二叠纪地区，每台钻机的水平活跃DUC数量已降至6.4口，其他主要油区为9.2口。在新冠疫情衰退之前，二叠纪的水平为3.9口，其他油区为6.4口。考虑到目前的活动和枯竭趋势，该行业可能会在9月底看到二叠纪盆地的完全正常化，并在9月至10月期间看到其他油区的完全正常化。
郝芬 译自 全球能源新闻网
原文如下:
US DRILLED UNCOMPLETED WELL INVENTORY TO LOWEST LEVEL SINCE 2013
US tight oil operators have for several months been depleting their inventory of drilled but uncompleted wells (DUCs) and, amid a slower drilling response, the number of ‘live’ DUCs in the country’s major oil regions slumped to 2,381 wells in June 2021, the lowest level since 2013, a Rystad Energy analysis reveals.
The total number of horizontal DUCs in the Permian, Eagle Ford, Bakken, Niobrara and Anadarko regions combined fell to 4,510 wells by the end of June. That implies a reduction of 1,800 wells from the peak of 6,340 in June 2020 and an average depletion of 150 wells per month over the past 12 months. The last time the size of the inventory was at this level was in the second half of 2018.
However, the total includes so-called ‘dead’ DUCs – or wells that were drilled more than 24 months earlier and remain uncompleted. Empirical evidence shows that more than 95% of wells drilled are typically completed within the first two years, and hence the probability of those more than two years old getting completed now are low. Therefore, including ‘dead’ DUCs to gauge future activity or forecast production is often more speculative.
“Looking at the number of remaining ‘live’ DUCs, a significant oil supply response from the US align="justify"> Live DUCs have declined across all major oil basins, with the Anadarko region the align="justify"> The Permian live DUC inventory level currently is comparable to the second and third quarters of 2019. The picture across other major oil basins is more dramatic. South Texas’ Eagle Ford and the Bakken align="justify"> A breakdown of the total tight oil DUC inventory by spud vintage, or the year the wells were spud, clearly shows that 2019-2020 vintages had a significant weightage align="justify"> In previous months, we repeatedly highlighted vintages from the fourth quarter of 2019 and the first three months of 2020 as key contributors of the unusually high DUC inventory build-up in the beginning of the Covid-19-induced downturn. By June 2021, 84% of those wells were completed. While it is still somewhat lower the 14-month depletion rate of 92-93% recorded for 4Q16-1Q17 and 4Q17-1Q18 vintages, it is comparable to the 87% posted for the 4Q18-1Q19 vintage between April 2019 and June 2020. Hence, this part of the DUC inventory anomaly has been largely eliminated by now.
While some degree of abnormality is still present, the industry is not that far off from a complete normalization of the DUC inventory level. The number of horizontal live DUCs per rig has already declined to 6.4 wells in the Permian and 9.2 in other major oil regions as of June 2021. Prior to the Covid-19 downturn, the level was at 3.9 for the Permian and 6.4 across other oil regions. Given the current activity and depletion trend, the industry will likely see a complete normalization by the end of September in the Permian, and by September-October across other oil regions.