Challenges and Achievements of Drilling Record MRC Wells for Appraising and Developing an Offshore Tight Carbonate

This paper describes the field development planning strategy for appraising and developing an offshore reservoir area via extended reach extra-long maximum reservoir contact laterals drilled from an artificial island. These single production and injection laterals are completed in excess of 20,000 ft on top of tens of thousands feet of drilled well path to reach the drain landing point. These laterals have a dual purpose, as in addition to reservoir appraisal, is to maximize the productivity and injectivity in an on-going development of a tight carbonate reservoir. The well planning process starts from a careful selection of reservoir target coordinates to maximize the oil in place being developed from the artificial island and to enable reservoir testing and appraisal. From this data, initial 3D well designs are generated based on island location and rig capability to ensure ability to drill and run completion to total depth. The generated well tracks are used in a reservoir model to forecast production uplifts and inflow/outflow profiling along laterals. A strategic drilling step-out program has been implemented to extend drilling reach and completion deployment incrementally along with a reservoir surveillance program. The program was designed with built-in risk mitigations for any potential drilling and completion issues. The implemented program has enabled drilling into new areas and testing the reservoir properties at a small incremental cost of extending horizontal laterals. This has led to huge cost savings versus a very expensive appraisal program from a wellhead platform that included drilling a new well in addition to topside facility changes and pipelines conversions along with associated maintenance costs. The data gathered from these wells have enabled reduction of geologic uncertainty and de-risking of future developments. As a result, the field development footprint of developed oil resources was extended by additional 20% without the requirement of building additional drilling structures. Additionally, there is a well count reduction via lateral extension thus leading to capital costs saving. There were initial challenges encountered during lower completion deployment but they were resolved successfully in subsequent wells. An outcome of this strategy was the successful drilling of maximum reservoir contact wells with tens of thousands feet of drilled well path to reach the drain landing point and then with single horizontal drains exceeding 20,000 ft. The drilled wells resulted in unprecedented records in UAE and globally in terms of well total length, horizontal drain length and completion deployment.

Efficient Wireless Drone Charging Pad for Any Landing Position and Orientation

A wireless charging pad for drones based on resonant magnetic technology to recharge the internal battery is presented. The goal of the study was to design a robust, reliable and efficient charging station where a drone can land to automatically recharge its battery. The components of the wireless power transfer (WPT) system on board the drone must be compact and light in order not to alter the payload of the drone. In this study, the non-planar receiving coil of the WPT system is integrated into the drone’s landing gear while the transmitting pad is designed to be efficient for any landing point and orientation of the drone in the charging pad area. To meet these requirements, power transmission is accomplished by an array of planar coils integrated into the ground base station. The configuration of the WPT coil system, including a three-dimensional receiving coil and a multicoil transmitter, is deeply analyzed to evaluate the performance of the WPT, considering potential lateral misalignment and rotation of the receiving coil due to imprecise drone landing. According to the proposed configuration, the battery of a light drone (2 kg in weight and 0.5 kg in payload) is recharged in less than an hour, with an efficiency always greater than 75%.

Lightning-induced high temperature and pressure microstructures in surface and subsurface fulgurites

Cloud-to-ground lightning causes both high-temperature and high-pressure metamorphism of rocks, forming rock fulgurite. We demonstrate that a range of microstructural features indicative of high temperatures and pressures can form in fulgurites at the surface and in fractures up to several meters below the surface. In comparison to a granite reference sample collected from a borehole at a depth of 138 m, microstructures in both the surface and fracture fulgurite are characterized by: (i) the presence of glass, (ii) a phase transformation in K-feldspar with the presence of exsolution lamellae of plagioclase, and (iii) high residual stresses up to 1.5 GPa. Since this is the first time that fracture-related fulgurite has been described, we also carried out a 1-D numerical model to investigate the processes by which these can form. The model shows that the electric current density in fractures up to 40 m from the landing point can be as high as that on the surface, providing an explanation for the occurrence of fracture-related fulgurites. Our work broadens the near-surface environments in which rock fulgurite has been reported, and provides a detailed description of microstructures that can be compared to those formed during other types of extreme metamorphic events.

Periodic points and smooth rays

Let P : C → C P: \mathbb {C} \to \mathbb {C} be a polynomial map with disconnected filled Julia set K P K_P and let z 0 z_0 be a repelling or parabolic periodic point of P P . We show that if the connected component of K P K_P containing z 0 z_0 is non-degenerate, then z 0 z_0 is the landing point of at least one smooth external ray. The statement is optimal in the sense that all but one cycle of rays landing at z 0 z_0 may be broken.

DEBARCADERE DE LOCODJRO ET DEVELOPPEMENT DE LA PECHE ARTISANALE EN COTE D’IVOIRE : DEFIS ET PERSPECTIVES / LOCODJRO LANDING STAGE AND DEVELOPMENT OF ARTISANAL FISHERIES IN CÔTE D'IVOIRE: CHALLENGES AND PROSPECTS

Considéré comme une véritable source d’espoir pour promouvoir la pêche artisanale en Côte d’Ivoire, le débarcadère de Locodro baptisé « Point de débarquement Mohammed VI » reste encore loin de répondre à cette attente après son ouverture en juin 2018. Cette situation suscite plusieurs interrogations sur les difficultés auxquelles il est confronté vu les commodités qu’il comporte pour être un excellent centre d’approvisionnement en produits halieutiques. Cette étude permet donc d’identifier ces difficultés, de montrer leurs conséquences sur la vie socio-économique des acteurs et de faire des recommandations pour la bonne marche dudit débarcadère. Pour la collecte des données, des documents traitant des thèmes en rapport avec la pêche ont été consultés. En plus, une enquête a été réalisée par le biais d’un questionnaire et des entretiens. Les résultats ont montré que les difficultés qui entravent le bon fonctionnement du débarcadère sont principalement liées à sa délocalisation d’Abobo-Doumé à Locodjro. Ces difficultés impactent négativement la vie socio-économique des acteurs. Cette situation qui suscite des inquiétudes recommande que des mesures correctives soient prises avec l’implication de toutes les parties concernées pour une rentabilité durable du débarcadère au profit de tous. Considered as a real source of hope to promote artisanal fishing in Côte d'Ivoire, the landing stage of Locodro named "Mohammed VI Landing Point" is still far from meeting this expectation after its opening in June 2018. This situation raises several questions about the difficulties it faces given the amenities it has to be an excellent supply centre for fishery products. This study therefore makes it possible to identify these difficulties, to show their consequences on the socio-economic life of the actors and to make recommendations for the good functioning of the said landing stage. For the collection of data, documents dealing with themes related to fishing were consulted. In addition, a survey was carried out by means of a questionnaire and interviews. The results showed that the difficulties hindering the proper functioning of the landing stage are mainly related to its relocation from Abobo-Doumé to Locodjro. These difficulties have a negative impact on the socio-economic life of the stakeholders. This situation, which gives rise to concern, recommends that corrective measures be taken with the involvement of all the parties concerned for a sustainable profitability of the landing stage for the benefit of all. <p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0896/a.php" alt="Hit counter" /></p>

Kajian Landing Station Alat Deteksi Dini Tsunami Berbasis Kabel Serat Optik Bawah Laut di Kabupaten Pasangkayu, Sulawesi Barat

The construction of an underwater fiber-optic cable-based tsunami early detection system is planned to be installed in the Makassar Strait with a landing point in West Sulawesi. Land infrastructure such as a Power House (PH), a communication tower, and a Beach Manhole (BMH) is needed to sustain the system's power in order to survive. Therefore, the aim of this scientific paper is to study several alternative landing station locations in Pasangkayu, West Sulawesi and then determine the priority locations. The methods used to achieve these objectives are field observation methods and secondary data analysis based on parameters of land area conditions, environmental conditions, supporting infrastructure, social conditions and licensing systems, and marine activities. These aspects are then assessed to determine the priority of the selected location. The location selected based on the assessment carried out is ALT-02B. In succession, the three priority locations selected from the order of most priority to least priority are ALT-02B, ALT-02A, and ALT-06. This selected priority location is not necessarily the final choice location to be used in the construction of a tsunami early detection system land infrastructure because in the process there are still things to be considered and aspects that are made the main priority for consideration in making decisions.

Anti-Collision Study for the Wells from New Artificial Islands Across Gigantic Mature Oil Field in Middle East Area

107 new wells are planned to be drilled primarily from two new Artificial Islands during the period of one project from 2023 to 2029. The number of existing wells in the oil field has reached 1,068 Mother bores, 2,178 wellbores @16,453,666ft total well length as of December 2019. Trajectories, especially from existing Artificial Islands, are getting more complex so as to avoid collision issues, and it is becoming increasingly difficult to drill accordingly. It is of great importance to assure that it is possible to drill the planned wells without serious collision issues before the execution of the project. Trajectories for planned wells were drafted one-by-one utilizing "DecisionSpace Well Planning" based on the predetermined slot allocation with the planned drilling pad design. Geological models are incorporated into DecisionSpace Well Planning. Therefore, formation tops were taken into account in order to make the trajectories more realistic. After that, trajectories were exported to "COMPASS" and anti-collision scan was performed on well-by-well basis. Anti-collision scan was performed among planned wells as well as actual wells. In case that one well has such serious collision issues that the well cannot/should not be planned based on company policy as a result of Anti-collision scan, trajectory or Landing Point (LP)/Total Depth (TD) location were adjusted. Then, Anti-collision scan was carried out again. If it was confirmed that there is no serious Anti-collision issues, trajectory was considered as final. It has been found that all the wells during the period from 2023 to 2029 can be drilled without serious collision issues by slightly adjusting LP/TD while satisfying several practical drilling requirements. Through the Anti-collision study, following recommendations for the avoidance of collision were obtained:Multi Station Analysis (MSA)+In-Field Referencing (IFR)+SAG correction should be applied in all the Jack up operations as well as Island operationsApplication of real-time MSA should be considered on a case-by-case basisMWD survey for the past wells should be corrected with IFR+MSA to reduce EOU sizeRe-Gyro jobs for low-quality survey wells should be enhanced around the project's development areaKick off point (KOP) should be deeper in the center of the drilling pad and shallower in the edge of the drilling pad

Design and Experimental Research of a New Type of Asteroid Anchoring System

Asteroid detection is of great significance to the study of the formation of the solar system and the origin of life. However, there are many types of asteroids, and they are far away from the earth, and the understanding of their various characteristics is not clear, which brings huge technical challenges to the landing and attachment of star catalogs. At present, the world is mainly based on surround, overflight, and short-term contact detection, and long-term attachment detection has not yet been realized. In order to solve the long-term attachment detection requirements of asteroids, focusing on the geological characteristics of various types of stars, this paper proposes a new type of asteroid attachment mechanism based on the beetle bionic theory, which can realize intelligent and flexible attachment and has strong adaptability. Around this design, this paper analyzes the mechanism of adhesion and realizes the adaptive matching of unascertained terrain landing point adhesion. On this basis, a prototype of the asteroid landing attachment mechanism was developed and verified by experiments. The experiment proved that the mechanism has strong multiterrain matching ability and can obtain an adhesion force of not less than 36 N on ordinary concrete ground.

Two-Stage Water Jet Landing Point Prediction Model for Intelligent Water Shooting Robot

In this paper, an intelligent water shooting robot system for situations of carrier shake and target movement is designed, which uses a 2 DOF (degree of freedom) robot as an actuator, a photoelectric camera to detect and track the desired target, and a gyroscope to keep the robot’s body stable when it is mounted on the motion carriers. Particularly, for the accurate shooting of the designed system, an online tuning model of the water jet landing point based on the back-propagation algorithm was proposed. The model has two stages. In the first stage, the polyfit function of Matlab is used to fit a model that satisfies the law of jet motion in ideal conditions without interference. In the second stage, the model uses the back-propagation algorithm to update the parameters online according to the visual feedback of the landing point position. The model established by this method can dynamically eliminate the interference of external factors and realize precise on-target shooting. The simulation results show that the model can dynamically adjust the parameters according to the state relationship between the landing point and the desired target, which keeps the predicted pitch angle error within 0.1°. In the test on the actual platform, when the landing point is 0.5 m away from the position of the desired target, the model only needs 0.3 s to adjust the water jet to hit the target. Compared to the state-of-the-art method, GA-BP (genetic algorithm-back-propagation), the proposed method’s predicted pitch angle error is within 0.1 degree with 1/4 model parameters, while costing 1/7 forward propagation time and 1/200 back-propagation calculation time.