By Sully Manope
The Ngisi-1 well, located 5km to the North East of the Chewa-1 well offshore Tanzania, has successfully encountered new gas pay zones as well as confirmed the northeastwards extent of reservoirs encountered in the Chewa discovery. “These wells have increased the mean recoverable resource of the Chewa-Pweza-Ngisi hub from 3.7 TCF to 4.5 TCF, in excess of pre-drill expectations, in addition to derisking exploration upside in several nearby targets”, according to Ophir Energy, which holds a 40% interest in Tanzania’s Block 4, with BG as 60% operator.
Ngisi-1, drilled by the Deepsea Metro I drillship, was designed to appraise the Chewa gas discovery drilled in 2010 and to penetrate the Ngisi exploration prospect. “On completion of the initial well, two sidetracks were undertaken to further delineate both Chewa and Ngisi. Gas pay was encountered in the Ngisi prospect within a high net to gross reservoir interval. The penetrations into the Chewa reservoir also encountered gas pay as prognosed and confirmed widespread, excellent reservoir characteristics”, Ophir enthuses.
The Deepsea Metro I drillship has now moved to drill the Mkizi-1 exploration well in Block 1. Mkizi is a 0.6 TCF prospect of Tertiary age, close to the Jodari discovery. After Mkizi, appraisal of the Block 4 Pweza discovery is planned.