American oilfield services firms secretly sustained Russia's oil industry after Ukraine invasion

Major U.S. oilfield services companies continued exporting equipment to Russia worth over $200 million after the invasion.
SLB was the largest supplier and recently announced it would stop exports to Russia.
The technology helped maintain Russia's economically critical oil production.
Other oil companies like Exxon and Shell exited Russia quickly after the invasion.
Oilfield services are vital for producing oil from Russia's challenging fields.