Determination of the mechanical properties of the rock in formation conditions

Object: Achimov deposits. West Siberian oil-and-gas province, Russia.

The purpose of the work: Determine the mechanical properties of the rock corresponding to the conditions of occurrence throughout the section.

Issues: The lack of results of core studies on mechanical properties in non-reservoir rocks; the results of previously conducted core studies do not reflect the properties of the rock under reservoir conditions.

Job Description:

As part of the work, complex core and petrophysical non-standard studies were conducted and analyzed, as a result of which the following results were obtained:

  • Along with the type of saturating fluid, the saturation method also affects the change in the elastic-strength characteristics of the substrate in the rock-fluid system. Saturation of samples by substitution is a "gentle" procedure and reflects the change in rock properties during fluid penetration in natural conditions, while the use of traditional saturation techniques is more consistent with the condition of the rock under prolonged exposure to fluid.
  • Conducting special core studies on groups of standard samples of doublers with a minimum of 6 pieces allows you to use a full set of standard geomechanical tests for key types of deposits and build strength certificates using various criteria.
  • When interpreting laboratory research data, it is important to adjust the results of acoustic measurements carried out under hydrostatic crimping conditions to reservoir conditions.

Result:

A holistic study of the system: reservoir deposits, interlayers and tires that interact with the reservoir fluid, coverage of all lithological differences and correction of the obtained values for reservoir conditions allowed us to obtain correct values of the geomechanical characteristics of the rock throughout the section, which increases the predictive power of the geomechanical model of the deposit.

In the implementation of this project accomplished: