Shares in Amerisur Resources (LSE:AMER) dived 15.8pc to 14.2p on Tuesday after the firm announced disappointing results from a key well at one of its part-owned fields in Colombia.
The Calao-1X exploration well was drilled to a final depth of 11,445ft on Amerisur’s 30pc held CPO-5 field, but no hydrocarbon potential was identified following the logging of the LS3 reservoir. Amerisur said that analysis indicates that the formation was encountered at a greater-than-expected depth and the well was based in an area without closure.
Alongside CPO-5’s operator, the firm is integrating the results of Calao-1X into the field’s general geophysical model while reviewing the model applied for another well called Pavo Real-1. Amerisur added that it is planning a further well on CPO-5’s Indico structure and that Calao-1X could potentially be used as a water disposal well in the future.
Elsewhere, the business provided an update on the workover programme currently being completed at its 100pc-owned Platanillo field in Colombia. It has completed work on a well called Platanillo-8 to install a selective completion. This allowed an 8ft interval of the target Lower U sand to be perforated and produced alongside existing production from the T sand. The interval is producing stably at 820bopd with an expected water cut of 17pc.
Amerisur’s workover rig has now moved to Platanillo-2, another well, where the firm expects to install a second selective completion and perforate the T sand. This will allow both U and T sands to produce simultaneously. It plans to carry out the same operation at a well called Platanillo-7 before drilling a new infill well called Platanillo-26. This will target an undrained area that has previously been identified on seismic.
The business will then re-enter two additional wells called Platanillo-22 and 21 to perform sidetracks that increase production.
Finally, in Tuesday’s update Amerisur revealed that its Q1 2019 working interest production is expected to fall to an average of c.4,600bopd. According to the business, this reflects the short term impact of production from a well called Inidico-1 being choked back from 1,100bopd to 330bopd.
Amerisur’s chief executive John Wardle said: ‘A disappointing result from Calao, however the information obtained from the well is allowing us to further refine our model in this important area, where we have already established material reserves through the drilling of Mariposa-1 and Indico-1. It is important to ensure that we fully re-evaluate Pavo Real-1X before committing to drill, and Amerisur has recommended to the Operator that drilling focus should return to the Indico structure for the moment, with the drilling of Indico-2, a low risk appraisal well. The Calao result has no impact on the previously disclosed CPO-5 reserves for year-end 2018.
‘The result of the Platanillo-8 workover was very positive, and we expect further success as our multi-well programme continues in that field. We also believe that the infill well Platanillo-26 is a low risk option to augment production in Platanillo and look forward to updating the market as that programme progresses.’