成熟领域

页岩井早期产量增加,然后产量下降速度比以往任何时候都快

维持页岩油生产的挑战越来越大。

人的剪影将石头推上山顶。 努力工作并取得成功的理念。 矢量插图设计。
数千口老油井的快速下降被新油井总产量的上升所掩盖。
Rewat Sombat/Getty Images/iStockphoto

根据 Enverus 的一份报告,美国页岩油井的平均产量每年下降得更快,迄今为止损失最大的是特拉华盆地。

随着行业工程师完成完井以最大限度地提高早期产量,新井总产量的上升掩盖了数千口老井的快速下降。

在按年比较平均下降曲线的图表中,每年的起点都比前一年更高,下降的速度也比前一年更陡。

报告作者兼 Enverus Intelligence Research 董事总经理 Dane Gregoris 表示:“美国页岩油行业取得了巨大成功,过去十年平均油井产量大约翻了一番,但近年来这一趋势有所放缓。” 。

报告称,自2010年以来,产量下降速度以每年0.5%以上的速度急剧下降。

“我们观察到,随着密度的增加,下降曲线(即产量随时间下降的速度)变得越来越陡。” 总而言之,该行业的跑步机正在加速,这将使产量增长比过去更加困难,”格雷戈里斯说。

下降幅度最大的是二叠纪特拉华盆地,该盆地的年下降率几乎是米德兰盆地 0.4% 的三倍。

该报告预测,产量下降将继续加速,因为某个区域内每增加一口井,就会显着加剧该地区井的产量下降速度。

新井产量低于老井这一事实并不令人意外。从历史上看,加密井的生产力低于最初的井。

但如果这些寿命已经很短的油井的递减曲线变得更加陡峭,那么钻探和压裂足够多的油井以实现持续增长的预测将面临更大的挑战。

更密集的压裂和更紧密的间距可以最大限度地提高初始产量,这代表了这些短命井的最终产量的大部分。

经过多年的集约开发,现在绝大多数已钻探的油井都位于老油井附近,这些油井已经耗尽了周围的油藏,从而减少了新油井的产量。

一般来说,二叠纪的剖面看起来更像其他富含石油的页岩气区,与二叠纪盆地相比,这些页岩气的开发开始得更早,而且可开发的资源也少得多。

石油价格的快速下降将减少这些油井的潜在产量和收入,从而推高新油井所需的盈亏平衡油价,而这些油井正在成为纯天然气生产商。

虽然天然气将提供稳定的现金流,但其价值低于石油,即使在天然气价值不像最近那样低迷的时期也是如此。

Enverus仍然预计,继续钻探将使美国石油产量增长,但加速下降将限制石油产量的最高水平。

虽然加密井维持生产的斗争是 SPE 论文的热门话题,但本报告中的数据(其中大部分仅限于付费客户)提供了对该问题的图形化评估。

美国能源信息署 (EIA) 8 月份钻井生产力报告称,二叠纪新井的产量将比老井的产量下降量少 3,000 桶/日。这一波动性行业的 1 个月快照并没有改变 EIA 对今年二叠纪产量增长的预测。

但现在看来,实现增长的新井收益似乎越来越难以实现。EIA表示,目前的新井产能低于2021年达到的最高水平。

它将当年强劲的新井数量归因于运营商限制了对最佳油井的开发,因为 2020 年 COVID-19 大流行油价暴跌后制定的预算紧张,仅对最佳油井进行了开发。

展望未来,美国能源信息署预测油价上涨,这可能会引发更多油井开发。钻探反弹将取决于油价是否高到足以证明增加支出是合理的。

堪萨斯城联邦储备银行最近对油田专家进行的一项调查得出的结论是,一桶石油(西德克萨斯中质油)需要价值 86 美元,才能证明大幅增加钻探是合理的。该价格高于 8 月 15 日的价格,尽管 EIA 短期展望表示该价格可能会在年底前达到该水平。

原文链接/jpt
Mature fields

Shale Wells Producing More Early On, Then Declining Faster Than Ever

The challenge of sustaining shale production is growing larger.

Silhouette of man push stone up to peak hill. Work hard and succeed concept. Vector illustration design.
Increasing rapid declines by many thousands of older wells are obscured by the rise in total production from new wells.
Rewat Sombat/Getty Images/iStockphoto

Production from the average US shale oil well is declining more rapidly every year, with the biggest losses by far in the Delaware Basin, according to a report from Enverus.

Increasing rapid declines by many thousands of older wells are obscured by the rise in total production from new wells as the industry engineers completions to maximize early production.

On a chart comparing average decline curves by year, each year begins higher and plunges at a steeper rate than the previous year.

“The US shale industry has been massively successful, roughly doubling the production out of the average oil well over the last decade, but that trend has slowed in recent years,” said Dane Gregoris, report author and managing director at Enverus Intelligence Research.

The production decline rate has grown steeper at a rate of more than 0.5% annually since 2010, the report said.

“We’ve observed that decline curves, meaning the rate at which production falls over time, are getting steeper as well density increases. Summed up, the industry’s treadmill is speeding up and this will make production growth more difficult than it was in the past,” Gregoris said.

The steepest declines are seen the Permian’s Delaware Basin, where the annual drop is nearly triple the 0.4% rate in the Midland Basin.

The report predicts declines will continue to accelerate because every well added within a section significantly steepens the decline rate for wells in that area.

The fact that new wells produce less than older ones is not a surprise. Historically, infill wells are less productive than the initial ones.

But if the decline curves on these already short-lived wells gets steeper, that will magnify the challenge of drilling and fracturing enough wells to deliver on predictions of continued growth.

More-intensive fracturing and tighter spacing can maximize the initial rate of production which represents much of the ultimate production of these short-lived wells.

After years of intensive development, the vast majority of the wells drilled now are near older ones that have depleted the surrounding reservoir, reducing the production from new wells.

Generally, the Permian’s profile is looking more like other oil-rich shale plays where development began sooner and there was far less to develop than in the Permian Basin.

Rapid declines will push up the breakeven oil price needed for new oil wells by reducing the potential production and revenue of these wells which are well on their way to becoming gas-only producers.

While gas will provide steady cash flow, it is worth less than oil, even in periods when the value of gas is not depressed as it has been recently.

Enverus still expects continued drilling will allow US oil production growth, but accelerating declines will limit how high that can go.

While the struggle to eke out production from infill wells is a popular topic for SPE papers, the numbers in this report—most of which are restricted to paying customers—offer a graphable assessment of the problem.

The US Energy Information Administration (EIA) Drilling Productivity Report for August said production added by new Permian wells will be 3,000 B/D short of the production declines from older wells. The 1-month snapshot in this volatile sector does not change the EIA’s Permian production growth prediction for the year.

But the new-well gains that have allowed growth now seem increasingly hard to come by. The EIA said that current new-well productivity is less that the high reached in 2021.

It attributed the strong new-well numbers that year to operators limiting development to the best wells during a year when tight budgets set after the 2020 COVID-19 pandemic oil-price crash limited development to only the best spots.

Looking ahead, the EIA predicts higher oil prices, which could spark more well development. A drilling rebound will depend on whether oil prices are high enough to justify increased spending.

A recent survey of oilfield experts by the Federal Reserve Bank of Kansas City concluded that a barrel of oil (West Texas Intermediate) would need to be worth $86 to justify a substantial increase in drilling. That price is higher than the price on 15 August, though the EIA Short-Term Outlook said it could get there by year end.