(Sharecast News) - Africa-focused oil and gas company Bowleven saw its shares jump on Friday after the spud of the IE-4 appraisal well at the Etinde block, Cameroon, by the block's operator, New Age Cameroon Offshore Petroleum.It is the second appraisal well do be drilled at the site this year by the Etinde joint venture partners, with drilling and logging operations on the well expected to take 90 days in total.Bowleven holds a 25% interest in the Etinde field and is partnered with LUKOIL, which holds a 37.5% interest.The IE-4 well is intended to target a previously undrilled sand package which is believed to be analogous to that at the IM-5 location, which exceeded expectations when drilled in 2013 when it encountered liquids-rich hydrocarbons.Drilling is expected to be required to a depth of 2840 metres in order to fully penetrate the prognosed reservoir targets, with a further "rat hole" of approximately 50 metres for logging sump.Bowleven's shares were up 9.93% at 33.50p at 1648 BST.