Optimizing Gas Production from Giant Multi-Reservoir Onshore Abu Dhabi Gas Field by Introducing Wellhead Compressors and Reconfiguring the Surface Network Using an Integrated Asset Model IAM

The giant onshore gas field in this study consists of six stacked reservoirs and has been producing for over three decades. The field has more than 150 gas producing wells and has several wells which have low-intermittent gas production rates. The low production is attributed to weak wells sharing common trunk lines with prolific wells. This study investigates the impact of choke optimization, surface network reconfiguration and wellhead compression to improve the gas production from weak wells after performing detailed analysis of possible root causes from the surface network by using an Integrated Asset Model (IAM) as the digital twin of the field. The investigation begins by identifying weak producers and involves studying the integrated surface network and determining the root causes for backflow and unstable hydraulics. After surface network issues have been recognized, remedial modification will be implemented. The impact of different choke settings on the wells are studied. The final step will be to introduce wellhead compressors on the weak producers. Extensive sensitivity scenarios are performed to identify the optimum compressor inlet pressure for each individual wellhead compressors and the wells which benefit most from the application of wellhead compressors are ranked. The multi-reservoir gas field contains six stacked reservoirs which are producing under depletion mode and share a common surface network. Root causes of weak or shut-in wells due to backflow or hydraulic issues are successfully identified by using an IAM simulation tool. The investigated remediations were simple optimization of the choke settings, reconfiguration of the surface network, and application of wellhead compressors to improve the gas production from the problematic wells. It is observed that the addition of wellhead compressors resulted in the most significant increase and more sustainable production from the weaker wells. Furthermore, the final selection of candidate wells for wellhead compressors can be dictated according to the highest gain from the ranking. The study revealed that the implementation of wellhead compressors will significantly increase the cumulative gas production from the selected wells at the end of field life and will result in positive production acceleration from the field perspective. This study shows that adding wellhead compressors to weak producers can mitigate the production bottlenecks and backflow issues and that higher and more sustainable gas production can be achieved from the weak wells after understanding the primary causes for low/intermittent production from the IAM which is acting as the digital twin of the field.

KAMPUNG LEUSER: TANTANGAN DAN PROSPEK SEBUAH PERMUKIMAN INFORMAL DI KEBAYORAN BARU

Kebayoran Baru was a well-planned new town. However, over time, Kebayoran Baru has been transforming, whether it is planned or not. One form of transformation in Kebayoran Baru has been the presence of informal settlements, such as those on Jalan Leuser. The kampong, which is claimed by its residents has been inhabited since 1955, has faced various challenges along the way, one of which is the threat of land expropriation and eviction. The threat of eviction stems from a land dispute involving the residents of Kampung Leuser as the party occupying the land and PAM Jaya as the party who claims to have rights to the land. Equiped with an HGB certificate under its name, PAM Jaya in 2016 requested residents to leave the land immediately. Residents who claimed to have lived on the land for more than 60 years firmly rejected PAM Jaya's claim and fought back. This study uses a qualitative research approach and a semi-autonomous social field perspective, aiming to understand the challenges of effective citizen control over the land and the prospects for future settlements. The challenges are formulated based on the background of the people's control over the land, the process, and its development until now. Meanwhile, prospects are presented through possible scenarios, either pessimistic, moderate, or optimistic scenarios. The results show that until now (2019), four years after the eviction plan began, Kampung Leuser still survives. In fact, the residents have also sued BPN as the party that issued the HGB certificate for PAM Jaya. This proves that the survival of Kampung Leuser is not impossible. Of the three scenarios that can be pursued in the future, the moderate scenario can provide a sense of justice for various parties. Furthermore, this dispute is expected to provide a lesson for the field of regional and urban planning, both practically and theoretically, regarding solutions in the management of informal settlements, both in the new city of Kebayoran Baru, as well as in other new cities in Indonesia.Keywords: informal settlements; semi-autonomous social field; Kampung Leuser – Kebayoran Baru AbstrakKebayoran Baru merupakan kota baru yang direncanakan dengan baik. Namun, seiring berjalannya waktu, Kebayoran Baru mengalami transformasi, baik direncanakan maupun tidak. Salah satu bentuk transformasi di Kebayoran Baru adalah hadirnya permukiman informal, seperti yang antara lain berada di Jalan Leuser. Kampung yang diklaim oleh warga telah dihuni sejak 1955 ini, dalam perjalanannya mengalami berbagai tantangan, salah satunya adalah ancaman pengambil-alihan lahan dan penggusuran. Ancaman penggusuran ini bermula dari sengketa tanah yang melibatkan pihak warga Kampung Leuser selaku pihak yang menempati lahan dan PAM Jaya selaku pihak yang mengklaim memiliki hak atas lahan tersebut. Berbekal sertifikat HGB atas namanya, pihak PAM Jaya pada 2016 meminta warga untuk segera meninggalkan lahan tersebut. Warga yang mengaku sudah tinggal di lahan tersebut sejak lebih dari 60 tahun dengan tegas menolak klaim pihak PAM Jaya dan melakukan perlawanan. Penelitian ini menggunakan pendekatan penelitian kualitatif dan perspeltif semi autonomous social field, bertujuan untuk memahami tantangan penguasaan efektif warga atas tanah tersebut, dan prospek permukimannya ke depan. Tantangan dirumuskan melalui latar belakang penguasaan warga atas lahan tersebut, proses, dan perkembangannya hingga saat ini. Sementara, prospek disajikan melalui skenario jalan keluar yang dapat ditempuh, baik skenario pesimis, moderat, maupun optimis. Hasil penelitian menunjukkan bahwa hingga saat ini (2019), empat tahun setelah rencana penggusuran bermula, Kampung Leuser masih bertahan. Bahkan, pihak warga juga sudah menggugat BPN selaku pihak yang mengeluarkan sertifikat HGB untuk PAM Jaya. Hal ini membuktikan bahwa bertahannya eksistensi Kampung Leuser bukanlah hal yang tidak mungkin. Dari tiga skenario yang dapat ditempuh ke depan, maka skenario moderat dapat memberikan rasa keadilan bagi berbagai pihak. Lebih jauh diharapkan sengketa ini dapat menjadi pembelajaran bagi bidang ilmu perencanaan wilayah dan kota baik secara praktis maupun teoritis mengenai solusi dalam pengelolaan permukiman informal, baik di kota baru Kebayoran Baru, maupun di kota-kota baru lainnya di Indonesia.

A Phase-Field Perspective on Mereotopology

Mereotopology is a concept rooted in analytical philosophy. The phase-field concept is based on mathematical physics and finds applications in materials engineering. The two concepts seem to be disjoint at a first glance. While mereotopology qualitatively describes static relations between things like x isConnected y (topology) or x isPartOf y (mereology) by first order logic and Boolean algebra, the phase-field concept describes the geometric shape of things and its dynamic evolution by drawing on a scalar field. The geometric shape of any thing is defined by its boundaries to one or more neighboring things. The notion and description of boundaries thus provides a bridge between mereotopology and the phase-field concept. The present article aims to relate phase-field expressions describing boundaries and especially triple junctions to their Boolean counterparts in mereotopology and contact algebra. An introductory overview on mereotopology is followed by an introduction to the phase-field concept already indicating first relations to mereo- topology. Mereotopological axioms and definitions are then discussed in detail from a phase-field perspective. A dedicated section introduces and discusses further notions of the isConnected relation emerging from the phase-field perspective like isSpatiallyConnected, isTemporallyConnected, isPhysicallyConnected, isPathConnected and wasConnected. Such relations introduce dynamics and thus physics into mereotopology as transitions from isDisconnected to isPartOf can be described.

A Flying Platform to Investigate Neuronal Correlates of Navigation in the Honey Bee (Apis mellifera)

Navigating animals combine multiple perceptual faculties, learn during exploration, retrieve multi-facetted memory contents, and exhibit goal-directedness as an expression of their current needs and motivations. Navigation in insects has been linked to a variety of underlying strategies such as path integration, view familiarity, visual beaconing, and goal-directed orientation with respect to previously learned ground structures. Most works, however, study navigation either from a field perspective, analyzing purely behavioral observations, or combine computational models with neurophysiological evidence obtained from lab experiments. The honey bee (Apis mellifera) has long been a popular model in the search for neural correlates of complex behaviors and exhibits extraordinary navigational capabilities. However, the neural basis for bee navigation has not yet been explored under natural conditions. Here, we propose a novel methodology to record from the brain of a copter-mounted honey bee. This way, the animal experiences natural multimodal sensory inputs in a natural environment that is familiar to her. We have developed a miniaturized electrophysiology recording system which is able to record spikes in the presence of time-varying electric noise from the copter's motors and rotors, and devised an experimental procedure to record from mushroom body extrinsic neurons (MBENs). We analyze the resulting electrophysiological data combined with a reconstruction of the animal's visual perception and find that the neural activity of MBENs is linked to sharp turns, possibly related to the relative motion of visual features. This method is a significant technological step toward recording brain activity of navigating honey bees under natural conditions. By providing all system specifications in an online repository, we hope to close a methodological gap and stimulate further research informing future computational models of insect navigation.

What do ‘peripersonal space measures’ really reflect? The action field perspective

The magnitude of a large number of behavioural and neurophysiological measures depends on the proximity between an individual and environmental objects. This relationship has led to the concept of peripersonal space (PPS). Here we argue that the proximity-dependence of such PPS measures could arise as a result of calculating the relevance of actions that aim to create or avoid contact with objects in the world. This perspective, supported by the interactive behaviour framework of systems-level brain function, allows us to describe PPS as a set of continuous fields reflecting contact-related action relevance. The action relevance perspective gets rid of incorrect notions about PPS, such as it being a single in-or-out zone that mainly reflects the spatial distance between objects and the body. This reconceptualization incorporates PPS into mainstream theories of action selection and behaviour. Furthermore, the formal comparison of this framework to others shows that contact-action value allows for a more complete description of PPS measures than proximity coding, impact prediction, and multisensory integration do, while simultaneously explaining the relationship between those concepts and PPS measures.

Albanian Transnational Social Field and Diaspora Entrepreneurs

This chapter and the following Chapter 5 are interconnected as they both discuss Albanian diaspora mobilizations. This chapter lays out political dynamics in the Albanian transnational social field and presents the profiles of the four types of diaspora entrepreneurs that operate within it. Incomplete nation-building and state-building processes have left Albanians scattered throughout the Balkans since the early twentieth century, where they currently live as either majorities or minorities. Weak state capacities of Kosovo alongside those of adjacent fragile states, as well as problematic treatment of Albanians where they are minorities, most notably North Macedonia and Serbia, have created dynamics conducive for Albanians to emigrate from the region and mobilize in the diaspora. Kosovo’s independence was a goal not simply for Albanians from Kosovo but was widespread among other diaspora Albanians until the 2008 independence. Albanians socialized with each other in the diaspora, irrespective of their original homeland, thereby forging bonds and seeking Kosovo’s statehood through a transnational social field perspective. More recently, another field-wide idea has emerged, of an ‘Albanian space’ formed through the EU integration of Balkan states with Albanian populations. This chapter presents data on migration in the Albanian field, in the Balkans and globally, and specifies the individual profiles of Albanian diaspora entrepreneurs.