Oil theft, spills and an urge to divest assets in Nigeria’s “swampy delta,” Reuters reported, has encouraged oil giant Shell — and a venture partner — to sell off Niger delta oil blocks.

In total, the four blocks produce 70,000 barrels of oil per day  and according to the report, oil production in the area has heightened.

Since June, Shell officials have been planning to reposition East African assets.

“Nigeria remains an important part of Shell’s portfolio, where we will continue to have a significant onshore presence in oil and gas,” Precious Okolobo, spokesman for Shell Nigeria told Reuters.

“Shell has a history of over 50 years in Nigeria and remains committed to the country and to supporting the government of Nigeria in their plans for the oil and gas sector,” he continued in a Vanguard report.

Oil licensing for blocks 18, 24, 25 and 29 have been put up for sale in addition to the 60.3-mile Nembe Creek Trunk Line, which produces 150,000 barrels per day, according to Vanguard.

Earlier this month, Shell had been dealing with leaks subsequently shutting down the line for repairs. While the company will be selling off block licenses, Shell will still assist local Nigerian companies which are looking to invest in the region — an initiative and process organized by the Nigerian government.

Vanguard also reported that domestic companies have already invested upwards of $5 billion in offshore oil fields.  In addition, Selling oil blocks — which Shell has done along with its joint venture partner since 2010 — have accounted for $2 billion in revenue and increased production.