Use of Microseismic in Monitoring Hydraulic Fractures in the Bakken Formation, North Dakota, USA
The Mississippian-Devonian Bakken Formation is a relatively tight mixed carbonate - clastics sequence in the Williston Basin of North Dakota. Although production can exceed 1000 BOPD, hydraulic fracturing is necessary to induce economic production. Until recently a great degree of uncertainty has existed regarding how the Bakken behaves during fracturing. In late 2007 seven (7) operators along with Schlumberger created a consortium that used the best available technologies to optimize understanding of certain geologic, drilling and completion principles that affect production. As part of this, three (3) horizontal wells (each 4000 feet in length) were drilled in an east - west direction, 1500 feet apart into the Middle Bakken Member. An array of 15 triaxial geophones, with 100 feet between each sensor set, was placed into the middle lateral (Nesson State 42X-36) to monitor the microseismic activity during the hydraulic fracturing of the two (2) outside wells. Different hydraulic fracturing methods were tried in each of the wells ranging from a single treatment in the northern lateral (Nesson State 41X-36) to a six (6) staged treatment with swell packers in the southern lateral (Nesson State 44X-36). The microseismic events were integrated with the geologic understanding of the area, radioactive and chemical tracers and reservoir simulation to develop a robust interpretation of effectiveness of the hydraulic fracture treatments.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009