Alun Cairns will today emphasise the UK Government's commitment to supporting the oil industry.
The Secretary of State will visit and tour Valero's refinery in Pembroke, where Vice President and general manager, Edward Tomp will update him on the company's operations.
He will then undertake a tour of the site to see up close the 220,000 barrel per day facility that is one of the largest fuel manufacturers in northwest Europe and one of the largest employers in the region.
With a workforce of over 500 people, with hundreds more employed as contractors, Valero refinery plays a pivotal role in the prosperity of the West Wales economy.
Speaking ahead of his visit, Alun Cairns will underline the company's continued investment in its Pembroke site as a testament to the strength of its people and the confidence it has in the business environment in Wales.
Secretary of State for Wales Alun Cairns said: "The oil industry is crucial to the UK's future energy security, economy and our cross-government industrial strategy.
"The contribution the Valero refinery makes to the regional and wider economies in Wales and the UK cannot be underestimated. Be it through job creation or community engagement, Valero plays a pivotal role in the lives of the people who live in this area.
"I want to make it clear that this industry has the full support of the UK Government.
"As one of the Wales' largest industrial sectors with one of the most highly skilled workforces in the world, we are determined to continue to work together to secure its long-term success.
"We will continue to ensure that we have the right policies in place to generate the necessary investment in energy infrastructure whilst ensuring important investors like Valero in Wales and the rest of the UK remain competitive."
Edward Tomp, Vice President and General Manager at Valero Pembroke Refinery said: "Valero is delighted to welcome the Secretary of State to Pembroke Refinery, so he can see for himself the impressive work being done day in, day out in West Wales in this vital industry. Being responsible for 15% of Welsh exports Valero is a major part of the economy in Wales and we are grateful for the UK Government's continued support for the downstream oil sector, which is key in terms of economic growth, employment and energy security for Wales and the UK."