An exploration deep well crossing two reservoirs with different quality and properties, having an objective of: Fluid identification and sampling in extremely tight section (∼0.02mD/cP mobility) as well as in another section that is suspected to be depleted with very high overbalance exceeding legacy tools, knowing the hydrostatic pressure being ∼9500psia. Wireline formation tester was run using single probe, leading to 65% of tight stations, the rest were valid but with very low mobility. This exposes the tool to an increasing pressure differential exceeding its physical limit and leading to damaging it. This makes any further analysis impossible. The toolstring was upgraded with latest technology of WFT, that is a merge between probe based and dual packer modules. This new technology was designed with extreme environments in mind, that allows sampling in all mobility range from extreme tight to very high with its capability of holding up to 8000psia differential pressure. In the job described here, some of the tested reservoir sections were differentially depleted, something unknown to customer as this was an exploration environment. Since this information were not know even after the completion of the first and second run, a third run was carried out with the objective of re-investigating the same depths performed by the single probe, but this time 3D Radial Probe was used instead. This gave the advantage of taking the pressure down to almost 0 psia. The potential hydrocarbon zone which was bypassed (seen dry with single probe) was then tested with 3D radial probe giving a reservoir pressure of 2864psia with a mobility of ∼300mD/cP where gas condensate was identified and captured. Now for the extreme tight reservoir section, in combination with high hydrostatic, the mechanical limitation of traditional tools remains the same making sampling and/or fluid ID impossible. An attempt was made using the 3D radial probe, and despite the extreme low mobility ∼0.02mD/cP, an identification of the reservoir fluid (water) was successfully completed without any issue. The use of 3D Radial Probe technology gave a completely different picture from what was expected, enabled the completion of all objectives and made the impossible (with conventional technology) possibly and easily achievable. This resulted in changing the well strategies accordingly and complete the well successfully. The new technology made the testing of unconventional reservoirs a reality.

Measuring in-situ stresses in unconventional formations constitutes a cornerstone for reservoir-quality and completion-quality evaluation. Challenges of succeeding these tests are related to difficulties to break these formations and propagate the created fracture allowing fracture gradient estimation. Moreover, formation heterogeneities and properties anisotropy, often lead to model inaccuracies and expose drilling or fracking operations to "avoidable" failures. Hence earlier in unconventional reservoir exploration, successful in-situ stresses become a must have for geomechanical model and Fracturing design calibrations. While cross-discipline integration is key to building a representative and comprehensive MEMs, since the early 2000's, Wireline Formation Testers are used to collect localized in-situ stress measurements that constitute a valuable input to fine-tune MEMs. However, with limited knowledge and inadequate planning, these operations known as "Micro-Frac/Stress Testing" are often challenged with high failure rate, especially with legacy tools physical limits. A combination of a novel stochastic planning approach involving the multidomain integration of Petrophysics, Borehole-Images and Geomechanics, coupled with Cutting-Edge WFTs technologies significantly increases the success likelihood for Stress Testing providing thereby an unfailing calibration source for MEMs. This new approach allowed first to define the depths to test with higher rate of success to break the formations and then, to communicate to drillers and client supervisor the test duration and potential adjustment such as mud weight, to break the rock and propagate the created fractures in the formations. The above enables, from operational standpoint, successful risk-free stress test measurement, allowing the calibration of the Mechanical Earth Model and Frac Design in the hydrocarbons embedded Source Rocks across South Algerian Basins. Furthermore, stress mapping allowed the identification of a lateral variability of stress gradients within the same field, confirming the unreliability of single-stress-gradient based models and highlighting the importance of multi-well modeling of mechanical earth properties. By using a well calibrated MEMs leading to a keen understanding of stress state, chances of stimulation operations success were significantly increased. The benefit of utilizing this new method with advanced logging technologies among which the new generation of WFTs, combined with a multidomain data integration as well as a novel planning approach based on stochastic simulation enabled the achievement of a failure-free Stress Testing operations, yielding fine-tuning of MEMs in the challenging South Algerian Hot Shale. Through a keen knowledge of stress state, stimulation operations success was significantly increased.