Kessler, Calvin (Halliburton Energy Services, Inc.) | Frisch, Gary (Halliburton Energy Services, Inc.) | Hyden, Ron (Halliburton Energy Services, Inc.) | Stegent, Neil (Halliburton Energy Services, Inc.)
Nuclear magnetic resonance (NMR) permeability combined with newly developed petrophysical analysis improves the candidate selection process for production-enhancement treatments such as matrix acidizing, acid fracturing, and traditional hydraulic proppant fracturing. The new petrophysical model allows automatic zoning based on log data such as permeability, stress contrasts, or lithology. The automatic zoning provides information for stimulation design, reservoir simulations, and economic forecasting.
Traditional stress zoning, which has enabled widespread usage of 3D modeling for the design of stimulation treatments, is now enhanced by an accurate permeability profile and automatic zoning. NMR logging provides a continuous, high-quality permeability that falls within the accuracy range required for 3D hydraulic-fracture design programs and reservoir simulators to predict production.
Combining the stimulation design and productivity calculations allows the operator to select the ideal stimulation treatment for the highest return on investment. The automatic zoning enhances both the stimulation design and reservoir simulations with minimal time and effort, allowing the operator to determine the most economical production enhancement scenarios, such as treatment type and job size.
Once the stimulation is performed, operators monitor the production rates and declines to enhance the process. Production data can lead to an improved NMR permeability by optimizing the permeability coefficients for area-specific permeability equations. The process is repeated for additional wells in the reservoir with the ultimate goal of optimizing the reservoir development.
Hydraulic fracture design with 3D models has been available to the industry for more than a decade. The integration of traditional porosity and saturation petrophysical analysis, stress profiling from log-derived elastic moduli, and pay cutoffs are the reservoir parameters needed for 3D modeling. Petrophysical models that perform reservoir zoning based on stress profile and net pay cutoff values have simplified the inputting of reservoir data into the 3D fracture design, increasing the usage of 3D fracture simulation.1-8
The value of production enhancement treatments is established, and stimulation methods have advanced greatly over the years.9-12 The relationship between treatment design/execution and expected production has not been fully developed, however. With the advent of NMR logging, petrophysical analysis can help answer the following questions:
What is the permeability of the zone?
Where are the hydrocarbons located?
Where is the water located?
Will the zone produce water?
Operators can combine this information with reservoir pressure data to determine
the rate at which the well will produce
the net present value (NPV) of the zone
The integration of NMR data with the stimulation processes has led to the development of the StiMRIL process, which is the link between reservoir description and optimized completion design.