Integrating Geology and Engineering for Viscous Oil Production Improvement—JX Oilfield, Bohai Bay, China

In this paper a case study is presented where refined 3D reservoir geology models, well pattern pilot test and Real-time GeoSteering tools have been integrated to optimize production performance of a viscous oil reserve. The viscous reserves were of high structural dip angle. In addition delta depositional system represented highly variable geomorphology, where stacked sandbodies and shale bedding are crossing each other frequently. In order to keep a higher production rate, using horizontal wells along with water injection was not enough;therefore, detailed reservoir characterization, well pattern pilot experiment and GeoSteering were used to optimize previous development strategy and keep horizontal trajectories safely landing into reservoir target zone. The stratigraphic sequence architecture that is derived from seismic interpretations captured the variation within these high dip structural backgrounds very effectively. The best combination of choices was “Injecting Water outside from OWC” and “Stair Shaped Horizontal Trajectories”. The borehole collision risks of these optimized strategies were then analyzed and controlled successfully by the GeoSteering tools during trajectory landing process. The reservoir development performance is improved tremendously as result of these renewed development strategies.

Strengthened Initialization of Adaptive Cross-Generation Differential Evolution

Adaptive Cross-Generation Differential Evolution(ACGDE)is a recently-introduced algorithm for solving multiobjective problems with remarkable performance compared to other evolutionary algorithms(EAs).However,its convergence and diversity are not satisfactory compared with the latest algorithms.In order to adapt to the current environment,ACGDE requires improvements in many aspects,such as its initialization and mutant operator.In this paper,an enhanced version is proposed,namely SIACGDE.It incorporates a strengthened initialization strategy and optimized parameters in contrast to its predecessor.These improvements make the direction of crossgeneration mutation more clearly and the ability of searching more efficiently.The experiments show that the new algorithm has better diversity and improves convergence to a certain extent.At the same time,SIACGDE outperforms other state-of-the-art algorithms on four metrics of 24 test problems.

High-entropy perovskite oxide BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ) with triple conduction for the air electrode of reversible protonic ceramic cells

Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stability of air electrodes exposed to concentrated vapor under operating conditions. Herein, we report a high-entropy air electrode with the composition BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ)(BCFZSP), which shows integrated electronic, protonic and oxygenic conduction in a single perovskite phase and excellent structural stability in concentrated steam. Such triple conduction can spread the electrochemically active sites of the air electrode to the overall electrode surface, thus optimizing the kinetics of the oxygen reduction and evolution reactions(0.448 Ω cm^(2) of polarization resistance at 550℃). As-prepared RPCCs with a BCFZSP air electrode at 600℃ achieved a peak power density of 0.68 W/cm^(2) in fuel-cell mode and a current density of 0.92 A/cm^(2) under a 1.3 V applied voltage in electrolysis mode. More importantly, the RPCCs demonstrate an encouragingly high stability during 120 h of reversible switching between the fuelcell and electrolysis modes. Given their excellent performance, high-entropy perovskites can be promising electrode materials for RPCCs.