Seplat Petroleum Development Company Plc is an oil and gas exploration company in Nigeria operating a portfolio of assets in the Niger Delta Region. This includes a 45% stake in OML 4 which covers an area of 267 square kilometres; a 45% stake in OML 38 which covers an area of 2 094 square kilometres; and a 45% stake in OML 41 that covers an area of 291 square kilometres. Seplat Petroleum Development Company Plc also holds a 40% non-operated working interest in OPL 283 marginal field which is located in the northern onshore deposit-belt of the Niger Delta; a 40% non-operated interest in OML 53 that covers an area of 1 585 square kilometres located onshore in north-eastern Niger Delta; and interest in OML 55 that covers an area of 840 square kilometres located in south-eastern Niger Delta. The companys head office is in Lagos, Nigeria.