(ShareCast News) - Sirius Petroleum has raised £850,000 gross at 0.5p a share following firm commitments from new and existing shareholders in respect of subscriptions for 170m shares.The net proceeds would be used for additional working capital purposes commensurate with Sirius' accelerated activities in Nigeria.It is preparing to bring its Ororo field into first oil production, in conjunction with its vendor finance consortium partners COSL Pan Pacific Drilling, Add Energy and Schlumberger.AIM-quoted Sirius added, in a separate statement, that it had entered into another milestone contract for the provision of an integrated services management (ISM) contract with Schlumberger. As part of Sirius' shallow offshore development strategy in Nigeria, the contract is for a multi-well campaign, which will commence in H1 2017.Schlumberger would provide Sirius with a comprehensive package of managed and integrated products and services including directional drilling services, logging, completion and production fluids, cementing and pumping services, well intervention and stimulation products and services, well testing services, wellsite communications and data and software solutions.The contract envisages a drilling programme on the Ororo Field and can be expanded to include other potential offshore assets.At about 14:43 GMT, shares in Sirius were up 4.54% to 0.58p.