Amerisur Resources has claimed a 100 per cent success rate from its Colombian drilling programme as oil production increases.The company's Platanillo field in Columbia has progressed despite some "logistical difficulties" affecting export.Production rose at Platanillo from 5,400 barrels of oil per day (BOPD) at the end of May to 7,100 after new wells came on stream. Amerisur calculates that the total field production could rise to 8,500 BOPD.The company said its efforts to develop alternative options to counter the logistical constraints were proving successful and the net impact had been "significantly reduced", with civil works expected to begin during June on the road construction to its nascent northern oil platforms.Amerisur continues to develop further export routes, at attractive pricing, to further support the development of the field.Chief Executive Dr. John Wardle said the board was encouraged by successful results from the Platanillo field. "We have now drilled seven new wells and performed two sidetracks of legacy wells with a 100% success rate. This is a very strong endorsement of the geological model and bodes well for the wells to the north." The road improvements to the northern road were said to be beginning imminently, allowing for further growth by allowing Amerisur to extend its reserves base into new areas.Added Wardle: "As we have already demonstrated, logistical issues can and will be addressed gradually to develop Platanillo to its full scale."Elsewhere in Colombia, new 2D seismic data from its Fenix block in the north of the country continues to be interpreted with a view to the drilling of a further exploration well later this year. Further down the continent, in Paraguay, a 500-point gravity survey has kicked off in Paraguay at the Piriti-Pilar complex basin.OH