Houston-based Vanguard Natural Resources LLC, which last year paid $1 billion-plus in an acquisition spree to acquire onshore properties, agreed Wednesday to sell some liquids-rich leases in Oklahoma’s stacked reservoirs to Titanium Exploration Partners LLC for $280 million.

Vanguard, which has an estimated 25,000 net acres in Oklahoma, works in the state’s two high-profile producing regions, the South Central Oklahoma Oil Province (SCOOP) and in the Sooner Trend of the Anadarko Basin, mostly in Canadian and Kingfisher counties, which producers refer to as the STACK.

The sale is expected to be completed by mid-May, after which Vanguard plans to update its operating and financial guidance. Proceeds would be used to reduce debt.

The publicly traded partnership has built an arsenal of assets across the onshore over the past three years in the Anadarko, Arkoma, Big Horn, Green River, Permian, Piceance, Powder River, Williston and Wind River basins, as well as along the Gulf Coast.

In one of two big deals in 2015, Vanguard paid $614 million to buy Houston-based Eagle Rock Energy Partners LP, which gave it natural gas-weighted operations in the Midcontinent, Permian Basin and in East Texas (see Shale Daily, May 22, 2015). Also last year Vanguard paid $535 million to buy LLR Energy LP, an onshore prospector with about 1.58 million net acres in the Permian and Arkoma basins.

Titanium, headquartered in Dallas is an oil and gas investment firm managed by co-founders Chip Simmons, who is CEO, and Executive Chairman Peter M. Halloran. Current assets consist primarily of reserves located in the Eagle Ford Shale and in the SCOOP/STACK area.