Multivariate Reservoir Property Modeling with Hierarchical Truncated Pluri-Gaussian and Projection Pursuit Multivariate Transformation Techniques

• Author / Creator

  Sunday, Chuks A

• To characterize a petroleum reservoir and to develop a reliable static and dynamic model for assessing resources and reserves, the rock and fluid properties of the subsurface formation are modeled. In most cases, multiple reservoir properties (categorical and continuous variables) are jointly utilized to represent rock properties. Standard practice is to model and characterize the categorical properties of the reservoir such as facies, before modeling the continuous petrophysical properties.

  A framework that applies the Hierarchical Truncated Pluri Gaussian (HTPG) and Projection Pursuit Multivariate Transformation (PPMT) techniques for multivariate modeling of rock properties in a petroleum reservoir is developed and documented in this thesis. The HTPG technique and PPMT workflow are established methods for modeling categorical and continuous variables, respectively. Unlike other truncated simulation techniques such as Truncated Gaussian Simulation (TGS) and Truncated Pluri Gaussian Simulation (TPGS), HTPG can be applied to a complex geological domain and does not limit the number of latent Gaussian variables that are used. Although the traditional modeling workflow for multivariate continuous property modeling reproduces important univariate statistics, it does not reproduce the complexity in the multivariate data, and this leads to models that do not reproduce important characteristics of the reservoir. To overcome this limitation and for ease in the geostatistical modeling workflow, the PPMT workflow is implemented. The PPMT decorrelates the multivariate variable and transforms them into univariate Gaussian variables that can be modeled independently.

  This proposed integrated modeling method is implemented on the Hekla Reservoir. The HTPG simulation technique is applied to model the five facies in the Hekla reservoir to generate one hundred simulated realizations of the facies, while the PPMT technique is subsequently applied to model the continuous petrophysical properties (porosity and permeability) distributed in the reservoir. This framework is reproducible and applicable to both mining and petroleum projects, which often require multiple categorical and continuous variables of geologic deposits or reservoirs.

• Subjects / Keywords

  • Categorical variable modeling
  • Facies modeling
  • Continuous variable modeling
  • Continuous petrophysical properties modeling
  • Geostatistical reservoir modeling
  • HTPG
  • PPMT
  • Gaussian simulation

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-39am-0z71

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.