Knowledge of the Rock Improves Completion Efficiency in Unconventional Reservoir - A Case Study
Smith, Charles H.; Menendez, Eli; Ziane, Lynda
Halliburton, Oklahoma City, OK.
Production results from unconventional reservoirs are difficult to predict and evaluate. Horizontal wells in resource plays that produce extremely well are sometimes surrounded by poor producers. One of the most frustrating aspects of these wells from the perspective of the completion is the inconsistency of fracture treatments to be effectively placed. In some wells, treatments pumped as designed, but in many other cases, breakdown was not achieved. Understanding the reservoir geology could help to understand these failures.
Various logging technologies have been attempted to assist in this understanding with varying degrees of success. A decision was made to establish a control case with an evaluation of conventional practices. In this control case, dipole sonic would be run after completion; the rock mechanical properties estimated from the dipole and the expected fracture treatment reaction of the rock would be compared to the actual treatment records.
A pilot well acquired geologic information through elemental capture, dipole sonic, and nuclear magnetic resonance to determine rock composition, vertical- and horizontal-rock mechanical properties, effective porosity, and permeability. After completing the horizontal drilling, dipole sonic was run through the horizontal section to determine anisotropy for breakdown initiation. These knowledge factors were used to target completion areas in the horizontal well and to design fracture treatments to create effective flow geometry from the reservoir to the wellbore.
This paper presents the case study of the completion data in the horizontal section of the pilot well. This pilot hole information was then used to develop treatment designs in the horizontal section of an offset well. The paper also presents that data. The results were extremely positive; improved knowledge of the reservoir geology resulted in improved fracture treatment placement.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012