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.

This paper describes a tailored multiskilling training program, newly designed for a group of students interns from different disciplines, that is based on the integration of different geoscience domains, leading to reinforce the technical competencies for future Petro-Technical workforce. The program was inspired by an initiative launched for experienced geoscientists from different disciplines (Geophysics, Geology, Petrophysics, Petroleum ...), planning to move or recently joined a consultancy team, to help understand the full picture of consulting projects. This program was downsized and re-tailored for MSc geoscience students. While traditionally each intern works on a specific project or thematic of his domain with a mentor from his discipline (i.e. Geology student with a Geologist ...), the cross disciplinary program assumes a group of students from different domain working together as one team, for 3-6 months internship, on a single integration-based project (Field Development Plan "FDP" in our case), during that period they will be supervised by mentors for each domain. Unlike conventional training program for students, as described in the previous section, the cross disciplinary approach allows each student to benefit from a theoretical courses-based learning in the form of class or web-based training for his domain, of course, as well as for other geoscience sub-disciplines, this is coupled with practical workshops and software learning/manipulation sessions. Hence, the intern will enrich his knowledge on other domains that were not necessarily covered during university courses. Looking outside of this mono-domain circle will help understanding what others are doing, how are they doing it, why are they doing it ... simply understand the way of thinking of each other across a consulting project team. The real benefit goes beyond that, in fact students from this program, when hired as Petro-Technical geoscientists, will easily integrate consultancy team of any size, know exactly what they have to do and why. The experience has demonstrated its effectiveness in preparing the future technical workforce. The cross-disciplinary training program for a group of students from different domains working on a unique project, is a new concept that has never existed before. In addition, for the first time ever, university has granted these students (although from different departments) to present their MSc graduation projects together as a single project in front of a larger technical committee to cover all the disciplines.

This paper has an objective of identifying the nature of formation fluid from an extreme tight fractured reservoir. A good understanding of petrophysical properties of the reservoir rock as well as the fluid it contains constitutes a real challenge for tight reservoirs, that are the most common unconventional sources of hydrocarbons. The front-line characterization mean is the Wireline logging which comes directly after drilling the well or while drilling, knowing that for low to extreme low porosity-permeability reservoirs any attempt of conventional well testing will not bring any added value not rather than a confirmation of reservoir tightness. A tailored workflow was adopted to design the most appropriate formation testing module, select the best depths for fluid sampling, and distinguish hydrocarbon from water bearing intervals. This workflow involves ultra-sonic and Electric Borehole Images in combination with Sonic Scanner for natural fractures detection, localization and characterization, integrating Dielectric recording and processing for petrophysical evaluation, then Formation Testing was carried out for fluid identification and sampling. The use of borehole electric and sonic imager coupled with advanced sonic acquisition helped not only to identify the natural fractures depths, but also the nature of these fractures. This integration was used for selecting the sampling station. Successful fluid sampling was carried out in 4 different depths (2 gas and 2 water), then a dielectric measurement was integrated to map the continuity of the water zone and narrow the uncertainty on fluid contact. This novel multidisciplinary approach that was adopted, integrates answer products from different domains to enable the interpreter, (the reservoir engineer, the geologist, and the Petrophysicist) to better understand and characterize the reservoir, toward a good reserve’s evaluation and appropriate development plan.

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