Successful Alternating Sequential Hydraulic Multifrac in Two Parallel Horizontal Wells in Low-Permeability Turbidite Oil Reservoir

Abstract A multistage fracturing treatment was performed in two adjacent horizontal wells (Escobal 197 and Escobal 195) in Chicontepec basin. The alternating sequential hydraulic multifrac in two parallel horizontal wells was planned and performed to create a high-density system of low-complexity planar fractures between the horizontal wells, to maximize the contact area with the reservoir and increase the stimulated reservoir volume (SRV). The wells were drilled perpendicularly to the expected fracture azimuth in Pechi-B formation and were completed as openhole using a ball-and-sleeve completion strategy. Thirty-two fracturing stages (16 stages per well) were selected based on an integral analysis of geological, petrophysical, and geomechanical disciplines. This completion technique has been the first stimulation treatment of its kind in Mexico. The fracturing entails adjacent wells in sequence, enabling one well to hold fracture pressure while the adjacent well is being fractured and it also maximizes the exposure of new reservoir rock. The fractures then avoid each other because of the stress pattern set up in the pressured well. The two adjacent horizontal wells were successfully stimulated in 108 hours of continuous work, pumping 95,000 bbl of fracturing fluid and 8.6 million lb of ceramic proppants. The stimulation technique reduced the stimulation cycle time to just four days, and the initial production of the two wells was more than 8,320 B/D, which was more than 10 times the average initial production in the area. The production later stabilized at 2,517 and 1,011 BOPD, respectively. The two horizontal wells produced 240,000 barrels in 90 days of cumulative production, which exceeds 14 times the average of cumulative production from the conventional wells in the field. The application of this completion technology was considered successful, and now it is extending to other fields located in the basin of Chicontepec.