Stress testing with inflatable packer assembly

An apparatus comprising:

• an inflatable packer assembly for use in a wellbore penetrating a subterranean formation, comprising:
• a first fixed sleeve fixed to a mandrel;
• a first sliding sleeve moveable along the mandrel;
• a first inflatable member connected to the first fixed sleeve and the first sliding sleeve;
• a second sliding sleeve moveable along the mandrel;
• a second inflatable member connected to the first sliding sleeve and the second sliding sleeve;
• a third sliding sleeve moveable along the mandrel;
• a third inflatable member connected to the second sliding sleeve and the third sliding sleeve;
• a second fixed sleeve fixed to the mandrel and slidably engaging the third sliding sleeve;
• a first inflation flowline disposed within the mandrel for inflating the first and third inflatable members to a first pressure;
• a second inflation flowline disposed within the mandrel for inflating the second inflatable member to a second pressure greater than the first pressure, wherein the inflated first, second, and third inflatable members isolate first and second portions of the wellbore;
• and
• an injection flowline disposed within the mandrel for injecting a fluid into at least one of the first and second isolated wellbore portions at a high enough pressure to enlarge microfractures in the subterranean formation.

A method comprising:

• conveying an inflatable packer assembly (IPA) in a wellbore such that first and second inflatable members of the IPA straddle at least a portion of a zone of interest of a subterranean formation penetrated by the wellbore;
• inflating the first and second inflatable members to radially expand the first and second inflatable members into sealing engagement with a wall of the wellbore and thereby isolate a portion of the wellbore, wherein the first inflatable member extends between a fixed sleeve of the IPA and a first sliding sleeve of the IPA, and wherein the second inflatable member extends between the first sliding sleeve and a second sliding sleeve of the IPA, such that inflating the first and second inflatable members moves the first sliding sleeve closer to the fixed sleeve and moves the second sliding sleeve closer to the fixed sleeve and the first sliding sleeve;
• injecting fluid into the isolated wellbore portion through a port of the first sliding sleeve to create or enlarge microfractures in the subterranean formation zone of interest;
• and
• after stopping the fluid injection, monitoring pressure in the isolated wellbore portion to determine a closing pressure of the microfractures.