By Nia Williams and Liz Hampton

CALGARY, Alberta/HOUSTON (Reuters) - Suncor Energy Inc (Toronto:SU.TO - News) is putting temporary infrastructure in place at its Mackay River oil sands facility in northern Alberta so it can remove oil from the plant by truck while a clogged pipeline is being cleared, two sources said on Wednesday.

The Enbridge Inc (Toronto:ENB.TO - News) pipeline blocked after heavy oil cooled in the system, prolonging a shutdown of the 38,000 barrel-per-day Mackay River thermal project.

Mackay River, along with a number of other oil sands operations, was shut down as a precaution in early May after a huge wildfire ripped through the Fort McMurray region, forcing producers to shut in more than 1 million bpd of crude.

One source said Suncor was aiming to transport around 10,000 bpd by truck and needed to move the bitumen volumes so it can keep producing and maintain pressure in its oil sands reservoir.

Both sources declined to be named because they are not authorized to speak to the media.

Thermal operations require ongoing steam injection to operate effectively and prolonged shutdowns raise the risk of upsetting delicate reservoirs.

Suncor did not immediately respond to a request for comment on whether it was trucking volumes from Mackay River, but has previously said the facility is expected to be operating at pre-wildfire production rates by mid-July.

"We anticipated there might be some minor operational hiccups in the restart and those were accounted for in our plan," spokeswoman Sneh Seetal said in an email.

(Reporting by Nia Williams; Editing by Matthew Lewis)