Integrating Petrophysical and Geomechanical Rock Properties for Determination of Fracability of the Iraqi Tight Oil Reservoir

Abstract

Tight oil reservoirs have been a concerned of the oil industry due to their substantial influence on oil production. Due to their poor permeability, numerous problems are encountered while producing from tight reservoirs. Petrophysical and geomechanical rock properties are essential for understanding and assessing the fracability of reservoirs, especially tight reservoirs, to enhance permeability. In this study, Saadi B reservoir in Halfaya Iraqi oil field is considered as the main tight reservoir. Petrophysical and geomechanical properties have been estimated using full-set well logs for a vertical well that penetrates Saadi reservoir and validated with support of diagnostic fracture injection test data employing standard equations and correlations. Subsequently, breakdown pressures are computed, and two fracturing models have been developed. The petrophysical analysis infers that the reservoir has poor properties, while the findings of the geomechanical properties indicate that the reservoir is brittle with ductile rock strata. These ductile strata underlay and overlay more brittle formations than the reservoir. The results from diagnostic fracture injection test DFIT are quite consistent with well logs results. The breakdown pressure reflects that this reservoir could easily be fractured by inserting pressure equal to 6250 psi. However, the fracturing model design parameters manipulates the fracture height confinement within Saadi Formation and its propagation to Hartha and/or Tanuma Formations. Therefore, the employment of petrophysical and geomechanical properties of the rocks assists in understanding the fracability of the formation and demonstrating the orientation and the fracture propagation direction.

Comparative Study between Different Oil Production Enhancement Scenarios in an Iraqi Tight Oil Reservoir

“…When designing a hydraulic fracturing treatment, it is important to prioritize the contact with the reservoir's capacity over the generated fracture half-length or conductivity. The length of the fracture produced has an impact on the effective fracture length and due to the complexity of the porosity-permeability and fracturing system, accurate flow modeling is critical for efficient treatment [6,10].…”

Petrophysical Analysis Based on Well Logging Data for Tight Carbonate Reservoir: The SADI Formation Case in Halfaya Oil Field

“…The majority of the limestone in the Sadi Formation is anticline. The Sadi reservoir has low to extra-low permeability, about less than 0.01 MD, while its porosity ranges from very poor to excellent, from 8% to 21% [38].…”

Estimation of the Petrophysical Properties of the Lower Cretaceous Yamama (YC) Formation in Siba Field

“…Porosity is caused by different geological, physical, and chemical processes, and it varies a lot between different types of rocks [14][15][16]. Reservoir characterization is the process of calculating the petrophysical characteristics of the earth's crust using data from seismic, seismic core, and well-log analysis [13,17,18]. Reservoir characterization aims to determine the petrophysical characteristics of a reservoir, such as its permeability, and porosity, at any depth and at any location [19,20].…”