A drilling rig casts its shadow on a lease owned by Elevation Resources near Midland, Texas U.S. February 12, 2019. Picture taken February 12, 2019. REUTERS/Nick Oxford 

An oil worker ascends a drilling rig on a lease owned by Elevation Resources near Midland, Texas U.S. February 12, 2019. Picture taken February 12, 2019. REUTERS/Nick Oxford 

A man walks near a drilling rig at a gas processing facility, operated by Gazprom company, at Bovanenkovo gas field on the Arctic Yamal peninsula, Russia May 21, 2019. Picture taken May 21, 2019. REUTERS/Maxim Shemetov 

A view shows valves near a drilling rig at a gas processing facility, operated by Gazprom company, at Bovanenkovo gas field on the Arctic Yamal peninsula, Russia May 21, 2019. Picture taken May 21, 2019. REUTERS/Maxim Shemetov 

Employees operate a drilling rig at a gas processing facility, operated by Gazprom company, at Bovanenkovo gas field on the Arctic Yamal peninsula, Russia May 21, 2019. Picture taken May 21, 2019. REUTERS/Maxim Shemetov 

A view shows a well head and a drilling rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A drilling crew member works at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A drilling crew member works at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A drilling crew member adjusts a pipe while working works at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

Drilling crew members move a pipe while working at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A view shows a drilling rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

Drilling crew members unload pipes in an oil rig at the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A drilling crew member works at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

A drilling crew member works at an oil rig in the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

Drilling crew members raise a drill pipe onto a drilling rig floor at the Yarakta Oil Field, owned by Irkutsk Oil Company (INK), in Irkutsk Region, Russia March 11, 2019. Picture taken March 11, 2019. REUTERS/Vasily Fedosenko 

The rig is seen on the drilling site of an exploratory borehole of Nagra, the Swiss National Cooperative for the Disposal of Radioactive Waste, near Buelach, Switzerland April 15, 2019. REUTERS/Arnd Wiegmann 

A pump jack operates in front of a drilling rig owned by Exxon near Carlsbad, New Mexico, U.S. February 11, 2019. Picture taken February 11, 2019. To match Insight USA-SHALE/MAJORS . REUTERS/Nick Oxford 

A drilling rig of Austria's oil and gas group OMV is seen at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A drilling rig of Austria's oil and gas group OMV is seen at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Pressure gauges are seen next to an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Drill pipes are seen next to an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A drill is seen on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker adjusts a drill pipe on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker adjusts a drill pipe on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Drill pipes are seen next to an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A drilling rig of Austria's oil and gas group OMV is seen at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Drill pipes are seen next to an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Workers walk towards an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Tools are seen at an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Work clothes are seen at an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Warning signs are seen at an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Drill pipes are seen next to an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker adjusts a drill on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker shows a plan at an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker adjusts a drill pipe on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

A worker watches a drill pipe on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Workers adjust a drill pipe on an oil rig of Austria's oil and gas group OMV at their exploratory drilling site near Maustrenk, Austria October 9, 2018. REUTERS/Leonhard Foeger 

Gauges monitor pressure on a drilling rig performing logging operations in the Permian Basin oil and natural gas production area near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling rig on a lease owned by Oasis Petroleum performs logging operations in the Permian Basin oil and natural gas producing area near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

Drill pipe is seen below a drilling rig on a lease owned by Oasis Petroleum in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling crew uses a mechanical roughneck machine to thread drill pipe together on an oil rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

Discarded drill pipe thread protectors are seen on a drilling rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling rig on a lease owned by Oasis Petroleum operates in the Permian Basin oil and natural gas production area near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling rig on a lease owned by Oasis Petroleum performs logging operations in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A member of a drilling crew prepares to place a collar around drill pipe on an oil rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

The operations floor of a drilling rig is seen from the control room on a lease owned by Oasis Petroleum in the Permian Basin near Wink, Texas U.S. August 22, 2018. REUTERS/Nick Oxford 

A drilling crew member raises drill pipe onto the drilling rig floor on an oil rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling crew member raises drill pipe onto the drilling rig floor on an oil rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A drilling crew moves drill pipe into place on an oil rig in the Permian Basin near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

Pump jacks operate in front of a drilling rig in an oil field in Midland, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

Horizontal drilling rigs operate in the Permian Basin oil production area near Wink, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A pump jack operates in front of a drilling rig at sunset in an oil field in Midland, Texas U.S. August 22, 2018. Picture taken August 22, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates in the Permian Basin near Midland, Texas U.S. August 23, 2018. Picture taken August 23, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates in the Permian Basin near Midland, Texas U.S. August 23, 2018. Picture taken August 23, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates at sunrise in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates at sunrise in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates at sunrise in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford 

A horizontal drilling rig on a lease owned by Parsley Energy operates at sunrise in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford 

A drilling crew leaves the rig at the end of their shift on a lease owned by Parsley Energy in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford 

A drilling crew leaves the rig at the end of their shift on a lease owned by Parsley Energy in the Permian Basin near Midland, Texas U.S. August 24, 2018. Picture taken August 24, 2018. REUTERS/Nick Oxford