bluuebunny/crossref_metadata_2025 huggingface dataset:
PERSPECTIVAS DO PROFISSIONAL DE GEOCIÊNCIAS EM UM CENÁRIO DE RETOMADA DE CRESCIMENTO ECONÔMICO BRASILEIRO.
Authors: Carneiro Celso Dal Ré
Published: January 2016

The work market in Geoscience will be deeply affected when the Brazilian economic growth be restored. Economic and political decisions can promote changes on the present scenaries. From the environmental conscience it is emerging a new ethics trending to a companionship where Man is recognized as an integer part of Nature without to feel special. The main trends in Geosciences comprise two linked professional fields: (a) the development of infrastructure – including prospecting for oil, gas, water and minerals as well as activities stimulating the productive economic sectors – and (b) the preservation of life and related infrastructure. Both branches must answer quite fast to strategical decisions. They are complementary and aim to develop harmonious relationships between Man and the environment. So, it is useless to define any relative priority between them.
GRANULITE FACIES ROCKS FROM GUAXUPÉ, MG: GNEISS-FLUID SEQUENCES AND P-T CONDITIONS
Authors: Choudhuri Asit , Silva Dailto , Nogueira José Renato , Sabó Gergely
Published: January 2016

Gnaisses de fácies granulito nos arredores de Guaxupé formaram-se em condições de P-T  estimadas em 8-9 Kb/800-900°C, e depois sofreram descompressão P-T-t  em virtude dosoerguimento. O limite inferior deste caminho é estimado em 5-6 Kb/600-700°C. Estudos de inclusões fluidas mostram fluidos de CO2, N2 E H2O dentro dos vários tipos de rochas pertencentes a esta sequência gnáissica, que resultaram da evolução da região. As isócoras para o CO2 estão compatíveis com a estimativa do limite inferior de P-T, dentro do fácies anfibolito. Entretanto, nenhum pico de fase rica em CO2, dos fluidos metamórficos foi detectado, podendo ser que o metamorfismo aconteceu sob as condições de ausência de fluido. Efeitos de alteração incipiente induzidos por fluidos na paragênese de fácies granulitos sugerem que o fluido pode não ter sido pervasivo, como pé comumente assumido para os terrenos de fácies granulito.
O PAPEL DO ANTEPARO NA MODELAGEM FÍSICA DE CINTURÕES COMPRESSIVOS – UM ESTUDO APLICADO A UM DUPLEX DO TIPO PILHA ANTIFORMAL
Authors: Gomes Caroline Janette Souza
Published: January 2016

In order to analyze the effect of a moving wall on experimental thrust systems, the progressive evolutionof antiformal stacks was simulated in sandbox models. The rigid, acrylic moving wall was substituted byanalogue material. Different boundary conditions demonstrated that in physical models the use of thehabitual stiff wall obstructs the development of the real architecture of compressional tectonics.
O CAMINHO DAS PEDRAS
Authors: Abreu Pedro Angelo Almeida
Published: January 2016

Application of modern geological concepts lead to the identification of different processes involvedin the geodynamic evolution of the southern Serra do Espinhaço, Minas Gerais, Brazil with special referenceto its depositional systems (Tab. 1 and 2), paleoclimatology and synsedimentary crustal extension history.Within this context a detailed analysis of the Espinhaço Rift, especially of the area Sopa - Guinda nearDiamantina (Fig. 1) lead to the identification of the precise magnitude of the source areas of the diamondscontained in the Sopa-Brumadinho Formation and consequently to the location of the primary sourcerocks of the diamonds.The primary source rocks of the diamonds (kimberlites or lamproites ?) are deeply altered either bycontemporaneous Proterozoic weathering or to less extent by recent weathering. The emplacement ofthose rocks along normal faults which controlled the local base level establishes a clear relation of causeand effect (consequence). The intrusions are coeval with the fault movements which defined adjacenttectonic cells where coarse clastics are deposited by the relief as well as the erosion products of the hostrocks ejected by the explosive volcanism (Fig. 4).The granulometric constancy of the conglomerates in the different alluvial fans, the uniform grade ofdiamond within these fans, and the absence of significant fluvial incision demonstrate that the system ofsynsedimentary normal faults was rift prograding, i.e. in the same direction as the sedimentary flow (Fig.4).On the other hand, the quartzitic breccia of the Campo Sampaio Member represents a vent brecciawhich accumulated in maar type craters, sometimes with local sedimentary reworking (Fig. 5).The individual characteristics of the diamonds of each of the diamond-bearing province within thesouthern Serra do Espinhaço (Fig. 1) suggest an intrinsic relationship of origin and space of the depository.Surface peculiarities of the diamonds are contrasting. Stones from the present three hydrographicbasins of the region show remarkable traces (unhas, jaças, many chips) of sedimentary reworking whereaslots of diamonds from conglomerates are found virtually intact, indicating negligible transport from theprimary source rock to the site of deposition within the Proterozoic coarse clastics.
NEOTECTÔNICA DA REGIÃO AMAZÔNICA: ASPECTOS TECTÔNICOS, GEOMORFOLÓGICOS E DEPOSICIONAIS
Authors: Costa João Batista Sena , Bemerguy Ruth Léa , Hasui Yociteru , Borges Maurício da Silva , Ferreira Júnior Carlos Roberto Paranhos , Bezerra Pedro Édson Leal , Costa Marcondes Lima da , Fernandes Jane Maria Garrafielo
Published: January 2016

Several types of structures are observed in the Precambrian, Mesozoic and Cenozoic rocks of theAmazon region, which represent the major features of the neotectonic framework developed since theMiocene. They controlled the sediment deposition of the Upper Tertiary and Quaternary, as well as haveinfluenced the development of the present landform patterns and drainage systems. Transpressive andtranstensive areas are recognized based on their nature and geometry, and related to two main episodes oftranscurrent displacement of Miocene/Pliocene and Upper Pleistocene /Recent ages. Sets of E-W, ENEWSWand NE-SW right-hand strike-slip faults are present in most of these areas. These sets are linked bynormal faults trending NW-SE and NNW-SSE, or by thrust faults trendig NE-SW and ENE-WSW,depending upon their geometry. Large areas with N-S trending younger normal faults are also observed.Earthquakes, the phenomenon of “fallen lands”, fluvial channels migration, hot springs, etc., are related toareas where some of these faults remain active. All these structures are related to an intraplate E-W righthandshear system induced by the rotation of South American Plate towards west.
RESUMO DE DISSERTAÇÕES DE MESTRADO
Authors: UFMG IGC -
Published: January 2016

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PEDOGEOMORFOLOGIA E MICROPEDOLOGIA DE UMA SEQUÊNCIA LATOSSOLO-AREIA QUARTZOSA HIDROMÓRFICA SOBRE ROCHAS CRISTALINAS DO ESTADO DO AMAZONAS
Authors: Andrade Hélcio , Schaefer Carlos Ernesto G. R. , Demattê José Luiz Ioriatti , Andrade Felipe Vaz
Published: January 2016

The pedogenesis of a latosol  plinthic podzolic latosol - hydromorphic quartzous sand sequence wasstudied, with respect to its chemical, physical and mineralogical properties. These soils are developed fromcrystalline substratum of the Guiana Complex, in the Occidental Amazon. The studied area is located inthe Waimiri-Atroari Indigenous reserve, at the Km 160 of the BR 174, which links Manaus to Caracaraí.The toposequence represents a hill formed by clayey soils in the top of the landscape, ending in a broadvalley flat with sandy soils in the bottom, under strong hydromorphism. The temperature and moistureregime of the soils are isohypertermic to hyperthermic, and udic to aquic, from the higher parts to the valleybottom, respectively. Six trenches were open and described in detail; in addition, core samples wereexaminated in six extra sites.Four soil profiles representatives of the segments ( latosolic, transition and hidromorphic) were selectedfor the study of physical , chemical, mineralogical and micromorphological characteristics of theircomponents. The higher part of the sequence is dominated by red-yellow latosol, the transition segment byplinthic podzolic intergrade to red-yellow latosol, and the lower parts by hidromorphic quartzous sand. Theparent material of the soil of all the sequence is heterogeneous, but basically derived from wheatheredgranitic rock, with some localized influence of alteration products of mafic rocks. All soils have a highaluminum saturation. In the higher parts of the sequence the textural gradient is lower and the clay fractionis dominated by kaolinite and crystalline iron oxides. Downslope the textural gradient increases and theiron forms are less crystalline. At the valley bottom rests a deep sandy mantle, where iron oxides are absent,remaining traces of kaolinite. Mica/illite were found in the deeper parts of the soils and hydroxide-interlayeredvermiculite in the upper parts. The sequence of evolution is processed mainly by pedological transformationinvolving seasonal acid and hydromorphic conditions, where ferrolysis occurs. This process leads to alateral degradation of the latosolic material of the top of the landscape, with clay destruction and concentrationof sandy materials dominated by quartz. Micropedological features related to the ferrolysis process arepresented and discussed.
A GEOMORFOLOGIA COMO CIÊNCIA DE APOIO AO PLANEJAMENTO URBANO EM MINAS GERAIS
Authors: Saadi Allaoua
Published: January 2016

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A INTERVENÇÃO DA GEOMORFOLOGIA NA VIABILIZAÇÃO AMBIENTAL DE UNIDADES HIDRELÉTRICAS-UHE’S: EXPERIÊNCIAS DE MINAS GERAIS
Authors: Saadi Allaoua
Published: January 2016

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A GEOMORFOLOGIA DO PLANALTO DO ESPINHAÇO SETENTRIONAL AVALIADA PARA A IMPLANTAÇÃO DE BARRAGEM: A HUE DE IRAPÉ – MG
Authors: Saadi Allaoua , Magalhães Jr Antônio Pereira
Published: January 2016

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PALEOCICLOS DEPOSICIONAIS E A MODERNA DINÂMICA FLUVIAL DO RIBEIRÃO DO CHIQUEIRO - DEPRESSÃO DE GOUVEIA/ESPINHAÇO MERIDIONAL - MG
Authors: Bueno Guilherme Taitson , Trindade Elaine de Sousa , Magalhães Jr. Antônio Pereira
Published: January 2016

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DINÂMICA FLUVIAL QUATERNÁRIA NO VALE DO RIO DO CERVOZONA RÚPTIL CARANDAÍ / MOGI GUAÇU / SUL DE MINAS GERAIS
Authors: Magalhães Antônio Pereira , Trindade Elaine de Souza
Published: January 2016

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A BIOGEOGRAFIA NO CONTEXTO DAS AVALIAÇÕES DE IMPACTO AMBIENTAL
Authors: Gontijo Bernardo Machado
Published: January 2016

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PROJETO CAMINHADAS ECOLÓGICAS ESTAÇÃO ECOLÓGICA/UFMG
Authors: Miranda Rodrigo Otávio da Silva , Ádamo Rodrigo , Neves Celso D’Amato Baeta , Gontijo Bernardo Machado
Published: January 2016

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“METODOLOGIA DE ELABORAÇÃO DA CARTA DO POTENCIAL EROSIVO DA BACIA DO RIO DAS VELHAS (MG)”
Authors: Soares Filho Britaldo Silveira , Carmo Valéria Amorim do , Nogueira Wagner J.
Published: January 2016

This paper concerns the methodology applied to the erosive potential analysis in the Rio da Velhashydrographic basin (Minas Gerais State, Brasil) along with the results obtained. This project aimed at theproduction of a digital map at a 1: 200 000 scale of the fragility of both natural and human-interferedenvironments in Rio das Velhas Basin. The adopted approach seeks to integrate the combined effects of aset of variables – relief, soil, climate and land use/land cover – to identify the environmental instability andto map the ecodynamic units. First, the cartographic variables were classified according to their degree ofenvironmental instability, these were later combined pair-wise and a set of decision rules was applied toproduce the final map. The results depicted well the major fragile areas in the basin, which should receivespecial care for their preservation. The developed methodology is easily implemented and flexible enoughto permit changing the decision rules to fit different criteria.
OURO BRANCO/AÇOMINAS: UM ÚLTIMO CAPÍTULO DA HISTÓRIA DA PRODUÇÃO DO ESPAÇO PARA A INDÚSTRIA?
Authors: Costa Heloisa S. M. , Costa Geraldo M.
Published: January 2016

The paper explores the close relationship between urbanization and industrialization in Minas Gerais throughthe case study of Açominas, a large scale steel mill built in the seventies and privatized in the eighties, andOuro Branco, a city planned and built as its urban support. The plan of the city is first discussed in the lightof national expectations concerning the expansion of that industrial branch at the time, and then comparedto other previous experiences of production of space as a result of industrial needs in other areas of MinasGerais. At the same time, some important implications are emphasized, as far as governance and the qualityof the urban space are concerned.Considering as a background the privatization of industry and a general restructuring of industrial production and goals, the paper explores some recent perspectives facing the future of both industry and the city. Someof the alternatives considered by the local leaders and administration include the diversification of activitiesand ecological tourism. It also argues that in a scenery of fierceful competition and constant change, theattributes of the planned urban space, despite its excludent character in social and spatial terms, are an assetthat differentiates Ouro Branco from other cities in similar position. Trabalho apresentado no VI Encontro Nacional da ANPUR, Recife, maio de 1997
A REDE DE CIDADES DO VALE DO JEQUITINHONHA NOS SÉCULOS XVIII E XIX
Authors: Velloso André , Matos Ralfo
Published: January 2016

The Jequitinhonha Valley, located in northeast Minas Gerais, presents itself in critical socio-economicstate. Its undervelopment and its peripheral condition in relation to the other areas of the state have becomechronic. Some of the contexts that have originated the current situation can be traced back to previoussocio-spacial configurations. The geo-historical analysis of these contexts surely allows a better understandingof the issue. The study of processes related to the structuring of an urban network in the region, iniciated bythe 18th century, helps to elucidate aspects related to the current state of affairs of the Valley. In this studythe networks, constituted by road linkages, flows and urban localities associated with the structure of theterritory, are analysed, taking into consideration that the improvement of the local conditions is deeplylinked to a broader understanding of its local history.
Resumos de Dissertações de Mestrado em Geologia - IGC/UFMG - 1997 e 1998
Authors: UFMG IGC -
Published: January 2016

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GEOCHRONOLOGY OF THE QUADRILÁTERO FERRÍFERO: A REVIEW
Authors: Noce Carlos Mauricio
Published: January 2016

Os estudos geocronológicos, especialmente com o uso do método U-Pb, tem sido fundamentais para oconhecimento da evolução arqueana do Quadrilátero Ferrífero. A região registra a atuação de diversoseventos magmáticos e tectono-metamórficos, entre 2860 e 2600 Ma. A datacão de rochas vulcânicasfélsicas em ca. 2772 Ma permite balizar a idade do Greenstone Belt Rio das Velhas. Tais vulcanitosfélsicos parecem posicionar-se próximo ao topo da sucessão basal do greenstone belt. Não se conhece aocorrência de rochas vulcânicas datáveis nas unidades supracrustais proterozóicas do Quadrilátero Ferrífero,de forma que suas idades de deposição podem apenas ser inferidas através das análises de zircões detríticos.A atuação da Orogenia Transamazônica na região encontra-se bem registrada, por meio da datação decorpos granitóides e eventos de metamorfismo entre 2120-2040 Ma.
INVESTIGAÇÕES ESTRUTURAIS DE UM DIQUE MÁFICO CAULINIZADO NA SERRA DO ESPINHAÇO MERIDIONAL, UTILIZANDO O GPR
Authors: Aranha Paulo Roberto Antunes , Horn Adolf Heinrich
Published: January 2016

The present work continues with the investigation of an intemperized and kaolinized intrusive mafic body.This body is localized south of Diamantina near the “Serra da Galinha”. These dike intruded units of theRio Paraúna (Bandeirinha Formation) and Espinhaço (Guinda Group) super groups.New field data are presented obtained by GPR and compared with borehole informations. Using these newdata and informations from literature it is able to give the form and the delimitations of the dike more exactly and describe the genesis of the kaolin, too.
DIREÇÃO DO TRANSPORTE SEDIMENTAR NA DESEMBOCADURA DO RIO ITANHÉM, EXTREMO SUL DA BAHIA, APLICAÇÃO DO MÉTODO DE GAO & COLLINS E KRIGAGEM VETORIAL
Authors: Ribeiro Luciano V. , Dupont Henri , Bodevan Emerson C. , Lúcio Paulo S.
Published: January 2016

A zona costeira do extremo sul da Bahia tem sido relacionada a diversos impactos ambientais incluindo odesmatamento da Floresta Atlântica, a erosão costeira e o assoreamento de desembocaduras de rios. Com ointuito de entender a dinâmica do transporte de sedimentos na desembocadura do rio Itanhém foram coletadas185 amostras de sedimentos de fundo distribuídas na área pesquisada. A metodologia adotada compara asvariações espaciais dos três parâmetros estatísticos média, desvio padrão (coeficiente de seleção) e assimetriaentre amostras vizinhas. Associações destas variações de parâmetros podem indicar a direção do transportede sedimentos. A associação mais usual determina que o sedimento torna-se mais fino, melhor selecionadoe mais negativamente assimétrico na direção do transporte. De um total de oito possibilidades de associaçãoda variação dos três parâmetros as três outras que mostram, também, uma melhora da seleção são, também,relacionadas ao transporte de sedimentos.A desembocadura do rio Itanhém recebe sedimentos tanto da deriva litorânea quanto da drenagem continental.Estes sedimentos tendem a acumular-se em bancos de areia, que formam um delta de maré vazante.Sedimentos são, também, transportados para montante do estuário através das correntes de maré enchentee são depositados na barra de pontal com acreção sedimentar lateral às margens do estuário.
Resumos de Dissertações de Mestrado em Geologia/ IGC/UFMG - 1999 e 2000
Authors: UFMG IGC -
Published: January 2016

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Determinants of Training Implementation and Intention in Lao Firms
Authors: Takahashi Yoshi , Somphon Vadsana
Published: January 2016

The present study aims to investigate determinants of training implementation and intention for firms in Lao PDR. In developing countries like Lao PDR in particular, enterprises are increasingly required to be internationally competitive through such efforts as developing human resources to deal with regionalization and globalization. Training is seen as a major way to develop human resources, but it has not yet been implemented intensively enough. Therefore, it is worth investigating the determinants of training in these firms. We utilize data from the Enterprise Survey 2013 by Deutsche Gesellschaft für Internationale Zusammenarbeit and analyze stratified random sample of 658 small and medium enterprises using ordinary least squares (OLS) and logistic regressions. The results are non-uniform among the different dependent variables, such as engagement in vocational training, the existence of training intention for entrepreneurs and employees, and skills variety of training premeditation for employers and employees. For instance, a gender of entrepreneur has a significantly positive effect on training implementation but an insignificant effect on training plan. Education of entrepreneur has an unconvincing effect on training execution but a significantly positive outcome on training will. Some other independent variables show more inconclusive but explainable results (e.g., firm size, competition problems, membership of a business organization, and age of entrepreneur). However, located in Vientiane Capital has a significant effect but firm-age and ethnicity of entrepreneur are insignificant. The results suggest to pay more careful attention to the potential differences among different training-related variables.
Study of an Oil Soluble Diverting Agent for Hydraulic Fracturing Treatment in Tight Oil and Gas Reservoirs
Authors: Zhao Xianzheng , Li Yongjun , Cai Bo , Hua Shen , Shi Yuanpeng , He Chunming , Li Shuai , Zhao Anjun
Published: January 2016

Nowadays, the fiber has become the most important oilfield chemical material with great advantages in hydraulic fracturing treatment when considering fluid leak off, proppant transportation and fracture damage in tight oil and gas reservoirs. However, it still has some drawbacks, such as mechanical properties, heat denaturation and poor chemical stability, always emerge in oilfield cases. Accordingly, a new type of oil soluble temporary diverting agent is used to overcome these shortcomings in our research. We developed into a new agent with different types of petroleum resin and hydrocarbon resin. A series of evaluation experiment was carried out including temperature compatibility, diverting efficiency and dispersity etc. The results showed that with increasing temperature and prolonging dissolved time, the oil soluble rate of temporary agent in 6 hrs was 95%-99% at 80-120 °C, which indicated good oil solubility. After complete dissolution, the viscosity of 5-20 g/L solution was 12.6-53.7 mPa.s, which had good flowback after treatment. Furthermore, by reducing the diverting particle size and improving the level of aggregation of particles, a specially designed instrument was put forward to evaluate the performances of fracture conductivity, fracture diverting. The length and concentration of the agent were optimized in this study.

More than 20 treatments with new agents in Huabei oil field have been performed with encouraging results, 95.2% efficiency with an average post-fracturing rate reach to 21.3m3/d, which was three times of before stimulation. The results have great influences on both theoretical study and field treatments of new chemical material for impoving complex fracure degree of hydraulic fracturing in tight oil and gas reservoirs.
Incorporating New Knowledge Significantly Improves Outcomes for Nascent Shale Gas Drilling in Cooper Basin
Authors: Yim M. , Ross A. I. , Healey S. , Leedham R. , Giuliano M.
Published: January 2016

This paper describes the procedures and methods used to successfully drill an extended reach horizontal well in Permian Shale Source Rock Reservoir, in the Cooper Basin, South Australia.

A previous attempt at a similar well design did not reach the objective. An independent review of this well's performance was used as a starting point to design an improved drilling program for the second well.

This included the following:

Closer liaison and collaboration was encouraged between the operator and the service providers. Improvements were planned for the second well to eliminate or reduce the severity of hole problems that occurred in the previous well. Written procedures were established to ensure that hole quality was maintained throughout the drilling phase. Technologies that could assist in improving drilling performance were identified, evaluated, and used.

As a result of these initiatives, the second well was considerably more successful than the 1st.

To compare and contrast the results of both wells as an indicator of improvement:

– The 1st well achieved only 37% of the objective. The 2nd well achieved 170% of the objective. – The 1st well exposed 589m of lateral wellbore. The 2nd well exposed 1014m of lateral wellbore – The 1st well required 38 days of drilling. The 2nd well was drilled in 11, despite being twice as long – The lateral in 1st well required 7 bits. The lateral in the 2nd well was drilled with 1 bit, again despite being twice as long – The 1st well observed 485 hours of NPT. The 2nd well was drilled with ZERO NPT.

The technologies and improved procedures used in the second well facilitated its success and these initiatives will be refined for future similar wells. The major contributors to difference between these two wells are:

Improved drilling fluid including the use of mud lubricant The use of drillstring torque-reducing subs improved bottomhole assembly (BHA) performance and reduced wear on downhole equipment. A new bit designed to match the rotary steerable system (RSS) tool and formation drilled the entire extended lateral and could have achieved even more.
Enhanced Sand Control of Multiple Branches Connected to a Single Wellbore
Authors: Durst Doug G.
Published: January 2016

Drilling, completing, and the production monitoring and control of multilateral wellbores in highly unconsolidated sandstone formations have achieved technical and operational success in recent past by ensuring that economic viability is attained and that well life is prolonged.

Gravel packing the lateral branch on a multilateral well is no longer a challenge. Sound isolation of the main branch is achieved to preserve the mainbore of debris when milling the window and drilling the lateral, which will ensure seamless gravel-pack operations. Stable junction isolation exists to support sand placement and the subsequent reverse-out of gravel-pack operations in both the main and lateral branch. Additionally, it is no longer considered a risk to run long, stiff, bottomhole completion assemblies across the window junction. One of the key factors in determining if a multilateral wellbore might be suitable for a given project is the type of sand-control completion and technique that might be required. The use of conventional standalone screens has a long and highly successful history. And now, where more sand-control reliability is required via use of gravel packs in combination with multilateral wellbores, technology is available and is also beginning to develop its own successful history.

Multiple successful installations of dual-bore, horizontal gravel-pack completions combined with Level-5 multilateral completion systems has resulted in increased reservoir drainage to improve the oil-recovery factor as well as the economic gains. In its current, form when combining advanced sandface completions with multilateral completions, the gravel-pack operations are followed by the installation of multilateral and upper completions. As a result of a newly developed system, one can now interconnect the junction completion with the sand-control operations in a single, seamless operation.
Advanced Geosteering Technology Promotes the Accuracy of Well Placement in the Thin Reservoirs of China Mature Oilfield
Authors: Hongsheng LI , Guofeng XIA , Daicai XU , Xuekai LI , Calleja-Djefel Bronwyn , Youquan LIU
Published: January 2016

After more than a decade of producing oil from the thick marine sand reservoirs in the HaDeXun oil field in the Tarim basin of western China, focus has shifted to the challenges of drilling thinly laminated reservoirs. To maximize efficiency and production, geosteering services, as well as bottomhole assembly (BHA) and bit optimization, were used for the successful drilling of two thin sands, which resulted in reservoir contact of 100 and 96%, respectively.

This paper presents a case study discussing prewell modeling, the planning process, execution, and results of drilling two complex thinly laminated reservoirs in a single well within a mature field. Each less than a meter thick, the thin reservoir targets are located above the main DongHeSha (DHS) sand reservoir and are bound by shale with uncertain formation dips. Adding to the complexity, the thin sands have limited lateral extension; however, recent improvements to well-placement technology have enabled these reserves to be recovered, which was almost impossible with previous conventional directional drilling methods.

An advanced well-placement process is discussed in the paper using azimuthal at-bit-gamma images and inclination measurements positioned only 1 m from the bit, a point-the-bit rotary steerable system, and modeling software for rapid, accurate data interpretation and pre-emptive wellbore positioning. Collaboration across teams resulted in an optimized BHA, which enabled directional changes to be made during the landing process to accommodate geosteering interpretations that refined the geological model to reduce uncertainties associated with the location of the reservoir top and bounding formation dips. Once landed, the well was successfully steered within the two thin sands, delivering one 303-m lateral section with 100% exposure to the reservoir and a second 300-m lateral section with 96% sand exposure.

This paper presents a practical workflow encompassing the integration of all available data, including seismic, offset-well petrophysical logs, mud logging, and real-time logging-while-drilling (LWD) images to overcome dip uncertainty and maintain the wellbore within the thinly laminated target sands. Also presented is a customized design of the BHA and drill bit, which were necessary during the landing portion of the drilling program and, when used together, helped reduce vibration, increase the rate of penetration (ROP), and enhance dogleg building capability to maximize reservoir exposure in a safe and efficient manner.
Why Multilateral Cemented Junction Wells Can Help Economics for Development Projects in Oil and Gas Shale Reserves
Authors: Vento Mario , Durst Doug
Published: January 2016

Multilateral wells have been routinely drilled for several applications, with shale plays representing a natural progression for its use. Augmenting a multilateral well with selective fracturing of each leg is as straightforward as fracturing a single horizontal well. Multilateral wells with cemented junctions provide a good alternative to improve the economics for the development of oil and gas shale-reserve projects. This paper provides a description of the primary reasons for improving development project economics.

Multilateral solutions provide the means to work within a limited surface access area and generate a reduced footprint while draining a much larger volume of the reservoir from a single-surface location. This solution presents a significant advantage when drilling in sensitive or restricted locations, populated areas, and areas in which land issues restrict access to multiple drilling locations. In addition, the cost and effects of large drilling pads or multiple wellsites are avoided.

This paper describes the results obtained from the implementation and execution of projects in which cemented junctions were created for a new dual-lateral well and for an existing well in North America. It also provides the average cost savings obtained when this approach is compared to that of a single main wellbore and describes well performance with commingled production rates above typical single horizontal wells.

Based on past experience, the use of multilateral wells with cemented junctions (applied for new and/or existing wells) can make significant contributions toward helping oil and gas shale-reserve projects to be economically feasible, whereas the economics of single horizontal wells do not offer advantages for a large development plan for oil-and-gas-industry operators.
High Build Up Rate Rotary Steerable System Leads to Revolutionize Onshore Horizontal Drilling in Western Desert of Egypt
Authors: Khattab H. M. , Ismail A. I. , Abdalla M. E. , Deraz S. , Helmy A. , Okasha M. , Samad H. A. , Ibrahim A. , Mansour M. , Muir D. , Vasicek A. G.
Published: January 2016

The drilling in the Western Desert area of Egypt is experiencing a shift from vertical to horizontal drilling.

Challenging geology, critical landing zones, complex well profiles, and tight lease boundaries lead to the requirement of High Build Up Rate (HBUR) values. This creates a drilling challenge with the limited capabilities of the current, commercial Rotary Steerable Systems (RSS).

The maximum Dogleg Severity (DLS) output capability for a RSS drilling 8–1/2 in hole size from most major directional drilling service providers is about 6.5° /100 ft. In soft formations, these doglegs output drop significantly and the RSS is replaced by a mud motor assembly. To overcome these challenges, the operator and directional drilling service provider teamed up to strengthen performance and consistency utilizing a new HBUR RSS technology coupled with an optimized bit design.

The operator and directional drilling service provider started a drilling campaign in 2013. The plan was to drill a HBUR curve in 8–1/2 in hole and land in the target zone with planned (DLS) in the range of 8.00 to 10.00° /100 ft. Then set a liner and drill 6 in lateral hole to the well TD. To date, this campaign has resulted in the successful drilling of three wells. The operator's costs were lowered through improved performance with the new HBUR RSS technology. The new technology reduced the number of trips and enabled faster curve drilling with pure rotary and better toolface control. The average number of drilling days per curve and lateral were reduced. In all cases, the curve HBUR planned rates were successfully achieved in a single run with optimum rate of penetration. This paper will discuss the case histories of the three successful wells. The benefits, cost savings and performance improvements of the HBUR RSS technology will be described for each well.
Enhanced Hydraulic Work-Over for Well Integrity Restoration
Authors: Romero Javier
Published: January 2016

The assurance of well integrity in the oil and gas fields has become a paramount responsibility during the field life cycle. Today this task represent a major challenge in the oil industry taking in consideration the rising of number of wells with extreme conditions with HPHT reservoirs, high fracture pressures, highly sour environments and subsea wells in ultra deep waters. After the catastrophic incident of Macondo in 2010, Process Safety (PS) and Well Integrity (WI), are the two major priorities of all Oil & Gas Companies, due to the potentially high financial and environmental impacts, in case a well barrier failure occur.

The management of the wells barrier represents one of the main targets inside the oil industry, in order to guarantee the integrity on the oil and gas wells. New standards highlight the requirement of to guarantee two barriers all the time in order to avoid any undesirable leakage of well fluids. The policy of ensuring two barriers is mandatory, and the aim is to have available a secondary barrier in case the primary barrier fail. However, immediately after any failure in the primary barrier, is also mandatory start up an emergency plan in order to recovery the primary barrier or suspend the Well properly with two temporary barriers. The emergency plan to re-establish two well barriers normally requires some special resources and an extensive risk assessment. The first challenge after the emergency plan has been activated is how to define an adequate and safer setup for the well intervention, in order to guarantee personnel safety and the integrity of the assets.

This technical paper propose a new approach for the Hydraulic Workover interventions and a workflow to enhance the Hydraulic Workover Units (HWOU) in order to make those operations safer, reliable and suitable to attend challenging interventions to restore wells with integrity issues and flexible enough and cost effective to attend conventional workovers. The idea is to develop an enhanced HWOU to compete with Rig, Hoist and CTU in different intervention scenarios. It’s presented an outline of the improvements, job analyis and the risk assessment required to define an adequate well control envelop in order to cover all the changes in the well barriers, the changes on well conditions and the expected challenges along the intervention. At the end we present the recipe to conduct the evaluation of every intervention and the tailored improvements to the intervention challenges.
Directional Casing While Drilling (CwD) Reestablished as Viable Technology in Saudi Arabia
Authors: Muñoz German , Dhafeeri Bader , Saggaf Hatem , Shaaban Hossam , Herrera Delimar C. , Osman Ahmed , Otaremwa Locus
Published: January 2016

To access the reservoir in a large Saudi Arabian development field, the operator is required to drill an intermediate 5,000 ft to 6,000 ft directional hole section with dogleg severity (DLS) varying from 2.5°/100 ft to 3°/100 ft. The commonly drilled 12¼-in. borehole crosses several interbedded formations comprised of limestone, shale and sands, and it is associated to a variety of hole problems, which present repeatedly in the offset wells. The main objective for the operator was to mitigate the problematic by defining alternative and suited drilling technologies. Among them, Saudi Aramco found that the recent developments in the directional casing while drilling (DCwD) technology may well provide an effective method for diminishing the associated nonproductive time (NPT).

The drilling engineering team conducted an extensive evaluation of the problems across this section, including wellbore stability, water flow, and loss of circulation; tight hole/stuck pipe incidents, severe bit/stabilizer wear while drilling abrasive sands. After a promising technical and engineering evaluation, followed by a detailed risk assessment aiming to determine the potential of the application, the selected well was planned and executed using the DCwD service.

This paper outlines the process carried out during all stages through the final deployment of the first 9⅝-in. DCwD application in Saudi Arabia, and how it successfully aided in achieving the goals by reducing the impact of some of the problems experienced while drilling the same section in previous wells in the field. Likewise, the information provided will serve as a starting point for the design and construction of subsequent wells leading to further improvement in drilling performance. Best practices and lessons learned from this implementation are expected to become a model and the know-how transferred to other areas where comparable drilling events occur.

The technological benefits have been recognized by the operator and this application reestablished DCwD as a viable technology to address a number of challenges common in many of the Saudi Arabian oil and gas fields.
High Performance Water Base Fluid Improves Wellbore Stability and Lowers Torque
Authors: DeNinno E. , Molina M. , Shipman J. , Dearing H. , Arpini F. , Bussaglia L.
Published: January 2016

In Southern Europe, a field known to have extremely unstable formations was drilled successfully with a specialized high- performance water-based fluid (HPWBF). Prior to formulating the HPWBF, laboratory analyses were performed on the formation using x-ray diffraction (XRD). The formation was found to be high in calcite, quartz and clays. The relative concentrations of the aforementioned minerals were variable; therefore, the samples' reactivities (measured by cation exchange capacities (CECs)) were also variable, increasing the difficulty of predicting reactivities when planning an appropriate drilling fluid. Previously, wells in this area endured costly and untimely sidetracks caused by stuck pipes and collapsing wellbores. The financial impact of lost time and equipment greatly reduced the profitability of the wells.

During the drilling program a drill pipe failure and subsequent fishing operations involved a successful recovery of the lost string and bit after nine days without circulation. Based off of previous experiences1,2, the laboratory formulated and piloted a HPWBF to solve these challenges. Using various shale inhibitors and a high-performance drilling enhancer (HPDE), the fluid stabilized the wellbore and delivered a low coefficient of friction for torque reduction. The HPWBF was also customized with a unique blend of viscosifying agents to maintain rheological properties for optimum hole cleaning.

The HPWBF stabilized the wellbore, allowing the pipe and bit to be retrieved and pulled out of the hole without any issues after the nine days without circulation. This discussion will include the formation's XRD and CEC findings, general drilling fluid measurements such as lubricity coefficients, rheologies, wellbore stability, lab tests on corrosion and cement contamination, and a comprehensive overview of the well data including torque drilling days.
Torque and Drag Modeling; Soft-string versus Stiff-string Models
Authors: Mirhaj S. A. , Kaarstad E. , Aadnoy B. S.
Published: January 2016

The wellbore friction, torque and drag, between drill string and the wellbore wall is one of the most critical issues which limits the drilling industry to go beyond a certain measured depth. For this reason many studies on torque & drag modeling have been performed. In this regard different approaches have been used; the difference in these approaches is often on how to include bending stiffness and shearing forces in the T&D calculations. These approaches are (1) the effect of shear forces calculations with the assumption of continuous contact of the wellbore wall and the drillstring as well as constant curvature trajectory, (2) the effect of bending stiffness and shearing forces calculations with assuming of clearance between drillstring and wellbore-wall and (3) the effect of bending moment and shearing forces, assuming continuous contact of the pipe and wellbore-wall and using a non-constant curvature trajectory in which the first and second derivatives of the curve exist (i.e. spline type trajectories).

This paper consists of two main parts: first a review on literatures on the subject of stiff-string T&D will be considered. Secondly, an approach will be discussed in which despite of the assumption of constant curvature trajectory and full-contact of pipe and wellbore wall, the effect of bending stiffness on torque and drag calculations are considered. The simple and robust stiff-string model is implemented in two example wells in order to find out the importance of the stiff-string calculations.
An Advanced Workflow for Determining Fracture Geometry in Complex, Tight Oil Formations in the Sultanate of Oman
Authors: Atanayev Askar , Nadezhdin Sergey , Zeidi Omar Al , Batmaz Taner , Kurnaidi Stevanus Dwi
Published: January 2016

Exploration drilling indicated that the Natih B formation in Oman may have a significant amount of oil locked in a challenging low-permeability, laminated, carbonate reservoir. The first completed vertical wells suggested that stimulation treatments were required for economic production. The operator applied acid fracturing stimulation techniques to establish baseline production. To further improve well performance, proppant fracturing stimulations were scheduled for several vertical and horizontal wells.

Mechanical earth models were constructed to help improve understanding of fracture geometry. The earth models revealed stress inversion between layers, differentiating stress regimes into strike-slip and thrust. Areas of different stresses within the same formation would lead to different hydraulic fracture shapes (e.g., regular planar fractures in the case of strike-slip mode or horizontal fractures in the case of thrust mode). Predicting these geometries would impact the fracture design and completion strategies. In addition, the pay zone was bounded by water-bearing zones at the top and bottom, introducing a risk of water production if any of the wells exhibited excessive fracture-height growth. Several measures helped survey fracture-height extension during initial diagnostic treatments.

In the formation's first horizontal well, uncertain stress regimes and lateral unconformities, such as natural fractures, complicated the hydraulic fracturing treatments. To overcome these uncertainties and optimize stimulation, we needed to accurately model natural and hydraulic fracture interaction. A mechanical earth model from vertical wells in the vicinity, and the horizontal wellbore itself, were combined with natural fracture network data and the staging and perforation design.
Use of a Life Cycle Drilling Simulation System on a Challenging HPHT Drilling Operation in the Norwegian Sea
Authors: Scott Laurie , Wessel Just Sverre , Nabavi Josef , Rommetveit Rolv
Published: January 2016

A Life Cycle Drilling Simulation System (LCDSS) was utilized during planning, training, and operation in support of a very challenging drilling operation in the Norwegian Sea. The LCDSS constitute a total modeling system tailor-made for planning, advanced training real-time simulation and decision support.

In order to utilize the LCDSS, the work processes were modified and fit-for-purpose communication lines were established.

In preparation, an advanced training session was performed using a dynamic downhole training simulator linked to a topside rig simulator, for training of the drilling teams.

Prior to operation data transfer was established so that during the operation simulations was performed in real time using the ongoing operational parameters as input.

Automatic look-ahead simulations of ECD and temperatures were performed with the calibrated models on the fly as support for decisions.

Every day drilling forecasts were made 12 to 24 hours ahead. This was done by means of a transient planning model populated with all relevant data from the operation. These forecasts were communicated to the drilling team as a basis for the upcoming operation.

This paper will first present the Life Cycle Drilling Simulation System, then elaborate on the use of this in the preparation/training phase and operational phase including forecasting. Special focus will be given to how the work process and communications were modified and the results thereof.

The operation was successful, and the LCDSS was a contributor to this.
New Concentric Dual-Diameter Fixed-Cutter Technology Bit Drills 35% Faster and Saves Operator Drilling Time Through Challenging Abrasive Sandstone in One of the Largest Reservoirs in the Middle East
Authors: Al-Ajmi Khaled , Al-Hamadi Ebrahim , Baqer Yousef , Al-Qnaai Mohammad , Fayed Moustafa , Khalil Karim
Published: January 2016

This paper will discuss the deployment of the concentric dual-diameter fixed-cutter bit technology, which was introduced in January 2015. The bit was deployed and tested twice in a vertical application in Burgan Field south of Kuwait and achieved the fastest penetration rate in the application.

The concentric dual-diameter bit is composed of a smaller pilot and a larger reamer section, where the reamer section dictates the final drill size. Conventional fixed-cutter bits take very little advantage of stress-relieving the rock, as it only affects the borehole wall. Concentric dual-diameter technology bits are able to initially drill with a leading smaller pilot section efficiently to relieve the stress of the rocks. Subsequently, the reamer section removes the stress-relieved rock with lower mechanical specific energy compared to regular fixed-cutter bits, giving it the advantage to generate higher penetration rates. Another advantage of the concentric dual-diameter technology bits is the stability of the bit, since two gauge sections are available to be in constant contact with the borehole while drilling.

The 12 ¼ in. concentric dual-diameter technology bit in conjunction with a packed rotary BHA was tested in a vertical application in the Burgan Field south of Kuwait. The bit was able to deliver improved performance, achieving the fastest penetration rate of 152.4 ft/hr. The section drilled was 762 ft in length and consisted of shale and sandstone.

The performance capability was confirmed when the same bit was reused again in a similar application subsequently and was able to deliver the same consistent record penetration rate of 152.5 ft/hr. The section length in this second run was 610 ft. and consisted of similar lithology of shale and sandstone.

The 12 ¼ in. concentric dual-diameter bit was able to surpass the average rate of penetration for the same application in the Burgan Field by 35%, saving the operator drilling time and making the concentric dual-diameter bit design the top performing drill bit in the field.