Colombia’s Cepcolsa has a multizone oil and gas discovery at the La Casona-1 well on the El Eden block in Colombia’s Llanos basin.
The well encountered hydrocarbon shows during drilling through the C7, Mirador, Gacheta, and Une reservoirs on its way to 16,450 ft measured total depth, said Petroamerica Oil Corp., Calgary, which has a 40% working interest in the block.
A petrophysical evaluation of logging-while-drilling and cased-hole logs indicates a total of more than 80 ft true vertical depth of potential net hydrocarbon pay in the well. The two primary reservoir objectives, Mirador and Une, have interpreted gross hydrocarbon-bearing columns of up to 40 ft (TVD) and 77 ft (TVD) and potential net pay thicknesses of 30.5 ft (TVD) and 50 ft (TVD), respectively.
The well was cased-off and the Une reservoir flow-tested using the drilling rig for more than 33 hr with intervening shut-ins. During the last and most representative flow period of 8 hr 30 min, the well produced under natural flow conditions 36° gravity light oil at an average rate of 1,200 b/d with 4 MMcfd of gas. Maximum oil rate was 1,288 b/d.
The wellhead flowing pressure was 3,010 psi, and the water cut at the end of the test was less than 0.8%. The well flow rate was restricted through a 20/64-in. choke due to gas flaring limitations. A workover rig will further assess the well’s ultimate flow potential and test other reservoirs with identified hydrocarbon pay. Of Petroamerica's 40% working interest in the El Eden block, 15% is still pending ANH approval.
Meanwhile, the Las Maracas-5 well on the Los Ocarros block, in which Petroamerica holds a 50% working interest, has reached a TD of 12,970 feet MD in the Une formation. Oil saturated cores were recovered from the Mirador and Gacheta reservoirs and are being analyzed.
The well has been logged and cased with the wireline log interpretation indicating more than 48 ft TVD of net oil pay in the Mirador and Gacheta sands, including a new Lower Gacheta sand with 15 ft TVD of net oil pay.
The well is under flow test, and thus far the new lower Gacheta sand has yielded over a 20-hr flow period, under natural flow through a 1-in. choke, an average 635 b/d of oil and a maximum rate of 754 b/d of 32° gravity API oil. Water cut at the end of the test was 0.3%.
The Middle Gacheta sand, which produces at the Las Maracas-3 and Las Maracas-4 wells, will be the next sand to be flow tested, after which the Tuscany 109 rig will drill the Las Maracas-6 well.
The Balay-4 development well in the southern part of Balay field where Petroamerica holds a 15% working interest, as of Nov. 13 was drilling at 8,567 ft MD in the Leon formation.