Located in the east-central sector of the Neuquén Basin, Loma la Lata is Argentina’s largest gas field with estimated reserves of 285 billion cubic meters. This mature field has been in development for over 30 years and has seen production declines of 30% in recent years. The latter, combined with a high demand for gas in the local market, created the impetus to evaluate new completion methods to improve production.
The Operator had drilled four open hole horizontal wells targeting the Sierras Blancas sandstone formation hoping that the increased reservoir access would boost production; however, only one well produced naturally. To increase production, fracture stimulation was performed using a conventional “plug and perf” completion on an offset well, but the procedure took 12 days to fracture only three stages. The Operator wanted a method that would be able to treat more stages in less time and place more proppant into the formation.
Four wells were completed with 5-stage Packers Plus StackFRAC® systems allowing for stimulation of all five stages in a single operation. The last well took only 2 hours to complete because all of the required proppant and fluids were on location allowing uninterrupted treatment. In one well, over 500,000 lb of proppant were distributed over the five stages covering approximately 800 m of open hole. This was three times the maximum amount of proppant ever placed in a horizontal Loma la Lata well using previous methods.
The StackFRAC system deployment achieved the Operator’s targets for increased stage number and proppant placement with reduced completion time. The cost savings realized from the latter alone was as much as $500,000 per completion. In addition, production from these wells was, on average, four times higher than offset wells with one well becoming the highest gas producer in the field.
Economic analysis indicated that hitting both the completion and production targets resulted in a 50% reduction in the payback period compared to unstimulated wells.