A Happy Ending for Shale Shut-Ins

Nearly all the shut-in unconventional US wells will be back in production in September, according to a report from Rystad Energy.

According to early reports, the output of the oil well was about the level before the closure, plus the output of the operator after the well opened.

“Nearly all operators said they did not face any issues in bringing volumes back on line as per schedule, as they had already worked on issues such as maintaining reservoir pressure and well integrity even before they began moderating output or shutting in wells,” said Veronika Akulinitseva, vice president of the North American Shale and Upstream for Rystad.

While there were talks about closing production and reducing output, the situation is quite the opposite.

“When operators shut in those wells in April–May, the downhole pressure started building, and when the wells are coming back on line now, operators are seeing short periods of increased oil productivity [and] also marginally lower gas/oil ratios in some cases,” Akulinitseva said. Based on the limited data the gains could be 10–15% for a few days up to a couple weeks.         

The operator talking about the subject has been EOG, which discussed the added output it calls “flush production” during its second-quarter investor call.  

“One observation from our production data revealed that almost every well exhibited some level of flush production before returning to its previous decline profile; further evidence showed that the well sustained no damage from the shut-in period,” said Billy Helms, the chief operating officer of EOG.

The explanation is that when they turn off production on these single-zone horizontal wells, the bottomhole pressure builds up as gas continues to flow in from the formation.

Helms said it has gone as expected, as shown in a slide from an EOG presentation in May.

[Source: https://pubs.spe.org/en/jpt/jpt-article-detail/?art=7491]


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