Sonatrach

About: Sonatrach is a company organization based out in Algiers, Algeria. It is known for research contribution in the topics: Hydraulic fracturing & Structural basin. The organization has 460 authors who have published 494 publications receiving 6339 citations. The organization is also known as: Sonatrach SPA.

Multiphased tectonic evolution of the Central Algerian margin from combined wide-angle and reflection seismic data off Tipaza, Algeria

Abstract: [1] The origin of the Algerian margin remains one of the key questions still discussed in the Western Mediterranean sea, due to the imprecise nature and kinematics of the associated basin during the Neogene. For the first time, the deep structure of the Maghrebian margin was explored during the SPIRAL seismic survey. In this work, we present a N-S transect off Tipaza (west of Algiers), a place where the margin broadens due to a topographic high (Khayr-al-Din Bank). New deep penetration seismic profiles allow us to image the sedimentary sequence in the Algerian basin and the crustal structure at the continent-ocean boundary. Modeling of the wide-angle data shows thinning of the basement, from more than 15km in the continental upper margin to only 5-6km of oceanic-type basement in the Algerian basin, and reveals a very narrow or absent transitional zone. Analysis of the deep structure of the margin indicates features inherited from its complex evolution: (1) an oceanic-type crust in the deep basin, (2) similarities with margins formed in a transform-type setting, (3) a progressive deepening of the whole sedimentary cover, and the thickening of the Plio-Quaternary sediments at the margin foot, coeval with (4) a downward flexure of the basement in the basin. These features argue for a multiphased evolution of the margin, including (1) an early stage of rifting and/or spreading, (2) a late transcurrent episode related to the westward migration of the Alboran domain, and (3) a diffuse Plio-Quaternary compressional reactivation of the margin.

Monitoring geological storage the In Salah Gas CO2 storage project

Abstract: Publisher Summary This chapter provides an update on the in Salah gas (ISG) project and the accompanying CO2 storage assurance project, which it is proposed and managed under the umbrella of a joint industry project (JIP). It consists of project management, establishing a project baseline, imaging CO2 migration, well based monitoring, rock/fluid interactions, detecting surface (geologic) seepage, integration and risk assessment, and communications. This CO2 project differs significantly in geological character and storage process from the existing Sleipner and Weyburn monitoring projects and offers an ideal opportunity to gain important additional information on the permanence and safety of CO2 geologic storage. The ISG project provides an important opportunity to study a gas field development project where geological storage at a field scale is employed to mitigate the environmental impact of the produced CO2 stream, which represents—60% of the projects emissions footprint.

Detection and measurement of surface cracks in ferromagnetic materials using eddy current testing

Abstract: Eddy current testing is used to detect and quantify defects in electric conductive materials. Defects investigated are specifically mechanical, chemical and microstructural heterogeneities. In this scope, artificial defects simulating superficial cracks have been achieved in order to establish an eventual relationship between the orientation, the shape and the size of the defect in one hand, and the signature that it generates in the impedance plane on the other hand. We determine in the first stage the operating conditions for the minimization of all signals that may perturb the crack signal such as the background one. We have been able to detect easily a surface crack on ferromagnetic steel in a large range of the frequency. Curves allowing the discrimination between signals corresponding to the presence of cracks and those corresponding to a lift-off have been established. The limit depth has as well been determined and we found that this limit has no relationship with the depth of penetration of the eddy current. The operative parameters such as the diameter and the working mode of the probe, the excitation frequency and the setting of the measurement equipment have been optimized for the testing of the quality and the reliability of critical ferromagnetic steel parts.

Predicting solubility of CO2 in brine by advanced machine learning systems: Application to carbon capture and sequestration

Abstract: Carbon dioxide (CO2) capture and sequestration in saline aquifers have turned into a key focus as it becomes an effective way to reduce CO2 in the atmosphere. The solubility of CO2 in brine is of vital role in monitoring CO2 sequestration. In this study, based on molality of NaCl, pressure and temperature, modeling of CO2 solubility in brine has been carried out utilizing multilayer perceptron (MLP) and radial basis function neural network (RBFNN). Levenberg-Marquardt (LM) algorithm was implemented to optimize the MLP model, while genetic algorithm (GA), particle swarm optimization (PSO) and artificial bee colony (ABC), were applied to optimize the RBFNN model. To this end, a widespread experimental databank including 570 data sets gathered from literature was considered to implement the proposed models. Graphical and statistical assessment criteria were considered to investigate the performances of these models. The obtained results revealed that all the proposed techniques are in excellent correspondence with experimental data. In addition, the performance analyses showed that RBFNN-ABC model exhibits the higher accuracy in the prediction of CO2 solubility in brine compared with the other proposed smart approaches and the existing well-known models. The RBFNN-ABC model yields a root mean square error (RMSE) value of 0.0289 and an R2 of 0.9967. Finally, the RBFNN-ABC model validity was confirmed and a small number of probable doubtful data was detected.