Geomechanics Open the Doors to New FrontiersWed, 01/20/2016 - 18:52
Over the past year, Ikon Science, a global leader in Quantitative Exploration and Development (QED), has been developing new workflows for onshore unconventional resource plays, providing value to drilling and completion engineers, in addition to its traditional geophysics and geology customers. According to Matt Bell, President of Ikon Science, the application of quantitative seismic interpretation, particularly in combination with geomechanics and geopressure prediction, is relatively underdeveloped in Mexico, which provides Ikon Science an opportunity to help unconventional resource developers identify, drill, and complete ‘sweet spots’ within the reservoir. “Unconventional reservoirs face a different set of production challenges from conventional reservoirs. Some of the major questions operators have surround the effective use of hydraulic fracture stimulation to deliver economic production rates,” Bell explains. He points out that the answers to these questions are rooted in geomechanics, as geomechanics plays a critical role in understanding the direction in which a stimulated fracture will grow, how far the fracture may grow horizontally and vertically, and whether the stimulated fracture will be a simple planar fracture or a complex network of fractures.
Bell notes that a fracture contained within a resource layer during stimulation is likely to yield higher production than a fracture that grows out of zone. The major control on fracture containment is the stress contrast between the resource layer and adjacent rock strata. This stress contrast can be captured by a calibrated geomechanical model. “Reservoir stimulation may result from new fractures being generated during the hydraulic stimulation process, from pre-existing fractures and planes of weakness being reactivated, or from a combination of both,” he details. The magnitude and orientation of the principal stresses, captured in a calibrated geomechanical model, and the relative orientation of pre-existing planes of weakness will determine whether new fractures are generated or preexisting fractures are reactivated. Similarly, the amount of stress anisotropy within the reservoir will govern the complexity of stimulated fractures.
When deepwater drilling was more active, Ikon Science was focused on helping companies understand formation pressures offshore in Mexico. Bell comments that wells targeting prospects in Mexican waters adjacent to highprofile discoveries in the Wilcox play, such as Tiber, Cascade, and Jack, may cost up to US$250 million to drill, and are likely to encounter high pressures, often while dealing with narrow drilling margins. Following recent changes in legislation, Bell has noticed increased interest in applying Ikon Science’s technology in Mexico, both onshore and offshore, especially in the Joint Impedance and Facies Inversion technology (Ji-Fi), which was launched internationally just over a year ago. “We are seeking pilot studies in Mexico, and would be happy to hear from any companies interested in trialing this radical technology on those fields.”
Ikon Science has developed a series of case studies from deepwater wells drilled in the Gulf of Mexico that demonstrate the value of the company’s pore pressure prediction and time-based data analysis methods. Given that geology does not change as activity moves across the US-Mexican border, Ikon Science can bring significant regional expertise to bear on local Mexican prospects. During drilling, it is critical to calibrate borehole stability and pore pressure predictions to known events, such as connection gases, tight hole conditions, and pack off tendencies. By performing its analysis on time-based data, much of which is done in real-time, Ikon Science can produce robust and accurate pore pressure predictions. In accordance to the company’s mantra, “the regional informs the local”, Bell expects that the understanding Ikon has gained in developing regional geopressure and rock property studies in the US Gulf of Mexico will transfer successfully to clients on the Mexican side.
In addition to regional, multi-client studies, Ikon Science is also willing to work on smaller, detailed investigations. The company’s 1D geomechanics workflow produces a highly detailed profile of strength and stress along a given wellbore in order to predict wellbore stability, fracture permeability, and fracture orientation. Depending upon the scope of the project, these 1D models can be used to populate highly complex 3D models, driven by seismic attributes, geostatistics, or both. The 3D models can be used for predrill stress and strength predictions, or as a part of more sophisticated models to address issues such as complex structure, salt dynamics, fluid flow, fault reactivation, subsidence, or changes in permeability