No description available.

Horizontal wells are a very important element in oil and gas industry due to their distinguished advantages. Horizontal wells are not technically horizontal. This is because of the structural nature of reservoir formations and drilling procedures. In response to the reservoir rock’s strength, the horizontal well deviates upward and downward while being drilled forming an undulating path instead of a horizontal. In this study, horizontal wells with an undulating trajectory within a gas reservoir have been studied. The aim of this research is to investigate the effect of the trajectory angle on pressure drop in horizontal wells. In addition, the contribution of water flow to pressure drop is a part of this research. Generally, water comes from different sources like an aquifer or a water flood job. In low permeability horizontal wells, hydraulic fracturing introduces water to gas wells. Water distribution is an important issue in gas wells production. In order to achieve the goal of this study, a model has been developed to simulate different situations for a horizontal well with an undulating trajectory in gas reservoirs. This study is a step forward to understand well performance in low permeability gas reservoirs.

No description available.

Water production is a challenge in production operations because it is generally costly to produce, treat, and it can hamper hydrocarbon production. This is especially true for gas wells in unconventional reservoirs like shale because the relatively low gas rates increase the economic impact of water handling costs. Therefore, we have considered the following questions regarding water production from shale gas wells: (1) What is the effect of water production on gas production? (2) What are the different water producing mechanisms? and (3) What is the water production potential of a new well in a given gas shale province. The first question was answered by reviewing relevant literature, highlighting observed deficiencies in previous approaches, and making recommendations for future work. The second question was answered using a spreadsheet based Water-Gas-Ratio analysis tool while the third question was investigated by using artificial neural networks (ANN) to decipher the relationship between completion, fracturing, and water production data. We will consequently use the defined relationship to predict the average water production for a new well drilled in the Barnett Shale. This study also derived additional insight into the production trends in the Barnett shale using standard statistical methods. The following conclusions were reached at the end of the study: 1) The observation that water production does not have long term deleterious effect on gas production from fractured wells in tight gas sands cannot be directly extended to fractured wells in gas shales because the two reservoir types do not have analogous production mechanisms. 2) Based on average operating conditions of well in the Barnett Shale, liquid loading was found to be an important phenomenon; especially for vertical wells. 3) A neural network was successfully used to predict average water production potential from a well drilled in the Barnett shale. Similar methodology can be used to predict average gas production potential. Results from this work can be utilized to mitigate risk of water problems in new Barnett Shale wells and predict water issues in other shale plays. Engineers will be provided a tool to predict potential for water production in new wells.

The large volume of water produced during the extraction of oil presents a significant problem due to the high cost of disposal in an environmentally friendly manner. On average, an estimated seven barrels of water is produced per barrel of oil in the US alone and the associated treatment and disposal cost is an estimated $5-10 billion. Besides making oil-water separation more complex, produced water also causes problems such as corrosion in the wellbore, decline in production rate and ultimate recovery of hydrocarbons and premature well or field abandonment. Water production can be more problematic during waterflooding in a highly heterogeneous reservoir with vertical communication between layers leading to unevenness in the flood front, cross-flow between high and low permeability layers and early water breakthrough from high permeability layers. Some of the different technologies that can be used to counteract this involve reducing the mobility of water or using a permeability block in the higher permeability, swept zones. This research was initiated to evaluate the potential effectiveness of the latter method, known as deep diverting gels (DDG) to plug thief zones deep within the reservoir and far from the injection well. To evaluate the performance of DDG, its injection was modeled, sensitivities run for a range of reservoir characteristics and conditions and an economic analysis was also performed. The performance of the DDG was then compared to other recovery methods, specifically waterflooding and polymer flooding from a technical and economic perspective. A literature review was performed on the background of injection profile control methods, their respective designs and technical capabilities. For the methods selected, Schlumberger's Eclipse software was used to simulate their behavior in a reservoir using realistic and simplified assumptions of reservoir characteristics and fluid properties. The simulation results obtained were then used to carry out economic analyses upon which conclusions and recommendations are based. These results show that the factor with the largest impact on the economic success of this method versus a polymer flood was the amount of incremental oil produced. By comparing net present values of the different methods, it was found that the polymer flood was the most successful with the highest NPV for each configuration followed by DDG.

Excess water production is a major economic and environmental problem for the oil and gas industry. The cost of processing excess water runs into billions of dollars. Polymer gel technology has been successfully used in controlling water influx without damaging hydrocarbon production in conventional naturally fractured or hydraulically fractured reservoirs. However, there has been no systematic investigation on effectiveness and placement conditions of polymer gels for shutting off water flow from fractures with narrow apertures in shale and tight gas reservoirs. The existing polymer gels, like those based on Chromium(III) Acetate, as a crosslinker will exert very high extrusion pressure to effectively penetrate the narrow aperture fractures present in shale and tight gas reservoirs. This gives rise to a need for a new polymer gel system that can be used for selectively shutting off water flow from narrow aperture fractures in shale and tight gas reservoirs. The new gel system will have a longer gelation time than the existing polymer gels; this ensures minimum crosslinking of the gel by the time it reaches bottom hole. The gelant solution will be pumped at low pressure so that, it penetrates only pre-existing fractures in the formation with ease. This study for the first time focuses on developing an environmentally benign polymer gel system based on high molecular weight HPAM, as a base polymer and a commercial grade PEI as an organic crosslinker. Gel samples of different concentration ratios of the polymer and crosslinker were prepared and classified under Sydansk code of gel strength to find optimum concentration ratios that gave good gels. The gel system was characterized using Brookfield DV-III Ultra Rheometer and Fann-35 Viscometer.

Made available in DSpace on 2014-06-11T19:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-05Bitstream added on 2014-06-13T20:46:41Z : No. of bitstreams: 1 ferreira_em_dr_guara_prot.pdf: 2582379 bytes, checksum: 9263a659ae78b3b2a0dfd7500e38a270 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A escassez da disponibilidade de água doce no mundo torna-se preocupante para os próximos anos e, apesar da crescente divulgação de tal situação, são poucas as pessoas que, na prática adotam uma postura consciente acerca da economia e uso racional do bem natural mais precioso existente. A presente tese apresenta uma proposta de produção de água potável a partir da água do mar pelo uso de processos de dessalinização associados a processos de cogeração, para que produzama energia térmica e elétrica para o funcionamento da instalação. A mesma é analisada com o uso de diferentes configurações, com vistas à otimização da instalação. São analisados 4 casos, verificando-se a viabilidade de sistemas de duplo propósito e sistemas híbridos, considerando-se, pelo lado do sistema de cogeração, a disputa entre diferentes conjuntos a gás de produção comercial, queimando gás natural ou biomassa gaseificada, com geradores de vapor, queimando óleo combustível ou biomassa in natura; pelo lado do sistema de dessalinização, concorrem unidades de osmose reversa acionadas térmica (ORS) ou eletricamente (ORE), unidades de evaporação (MED) e de destilação (MSF); no atendimento ás necessidades de vapor concorrem turbinas de contrapressão e condensação/extração. Foram analisados dados referentes à cidade litorânea de Ubatuba, SP, para avaliação do atendimento conjunto das necessidades de energia elétrica ee água potável para o abastecimento de situações limítrofes, como ocorre durante os picos de consumo de verão. Conclui-se que a proposta é viável para os casos analisados, podendo haver a possibilidade de venda de excedente energético, de acordo com o nível de produção da unidade como um todo. / World's fresh water availability scarcity is becoming a concerning problem day by day, and depende the increasing of the alarming new about such situation, just a few people adopt a positive position about the economy and rational use os this precious natural resource. This thesis presents a fresh water production proposal from seawater by desalination processes associated to cogeneration processes for producing the necessary thermal and electric energy for the whole installation. The dual-purpose systems is analyzed with the use of differente configurations by an optimization viewpoint. Four cases are analyzed with hybrid and dua purpose systems availability verification. The considerations, with respect to cogeneration were the use different commercial gas turbines, burning natural gas or gasified biomass, with or without steam generator, burning fuel oil or biomass in natura. For desalination system, it wasallowed the choice of reverse osmosi thermally driven (ROS) reverse osmosis elctrically driven (ROE), evaporation (MED) and distillation (MSF) units. Also, the steam supply system could be constituted of backpressure and extraction-condensation turbines. The data analyzed here refers to the Ubatuba coastal city, situated in the São Paulo Statte - Brazil, the relationship between the electrical energy and fresh water simultaneous supplying for extrem situations, like it occurs during summer consumption peaks was analyzed. The present study concluded that the analyzed cases were feasible, with the possibility of energetic surplus selling, according to the unit production operational level.

Resumo: A escassez da disponibilidade de água doce no mundo torna-se preocupante para os próximos anos e, apesar da crescente divulgação de tal situação, são poucas as pessoas que, na prática adotam uma postura consciente acerca da economia e uso racional do bem natural mais precioso existente. A presente tese apresenta uma proposta de produção de água potável a partir da água do mar pelo uso de processos de dessalinização associados a processos de cogeração, para que produzama energia térmica e elétrica para o funcionamento da instalação. A mesma é analisada com o uso de diferentes configurações, com vistas à otimização da instalação. São analisados 4 casos, verificando-se a viabilidade de sistemas de duplo propósito e sistemas híbridos, considerando-se, pelo lado do sistema de cogeração, a disputa entre diferentes conjuntos a gás de produção comercial, queimando gás natural ou biomassa gaseificada, com geradores de vapor, queimando óleo combustível ou biomassa in natura; pelo lado do sistema de dessalinização, concorrem unidades de osmose reversa acionadas térmica (ORS) ou eletricamente (ORE), unidades de evaporação (MED) e de destilação (MSF); no atendimento ás necessidades de vapor concorrem turbinas de contrapressão e condensação/extração. Foram analisados dados referentes à cidade litorânea de Ubatuba, SP, para avaliação do atendimento conjunto das necessidades de energia elétrica ee água potável para o abastecimento de situações limítrofes, como ocorre durante os picos de consumo de verão. Conclui-se que a proposta é viável para os casos analisados, podendo haver a possibilidade de venda de excedente energético, de acordo com o nível de produção da unidade como um todo. / Abstract: World's fresh water availability scarcity is becoming a concerning problem day by day, and depende the increasing of the alarming new about such situation, just a few people adopt a positive position about the economy and rational use os this precious natural resource. This thesis presents a fresh water production proposal from seawater by desalination processes associated to cogeneration processes for producing the necessary thermal and electric energy for the whole installation. The dual-purpose systems is analyzed with the use of differente configurations by an optimization viewpoint. Four cases are analyzed with hybrid and dua purpose systems availability verification. The considerations, with respect to cogeneration were the use different commercial gas turbines, burning natural gas or gasified biomass, with or without steam generator, burning fuel oil or biomass in natura. For desalination system, it wasallowed the choice of reverse osmosi thermally driven (ROS) reverse osmosis elctrically driven (ROE), evaporation (MED) and distillation (MSF) units. Also, the steam supply system could be constituted of backpressure and extraction-condensation turbines. The data analyzed here refers to the Ubatuba coastal city, situated in the São Paulo Statte - Brazil, the relationship between the electrical energy and fresh water simultaneous supplying for extrem situations, like it occurs during summer consumption peaks was analyzed. The present study concluded that the analyzed cases were feasible, with the possibility of energetic surplus selling, according to the unit production operational level. / Orientador: José Antonio Perrella Balestieri / Coorientador: Mauricio Araujo Zanardi / Banca: Paulo Magalhães Filho / Banca: Ricardo Alan Verdú Ramos / Banca: Rogério José da Silva / Banca: Miguel Edgar Morales Udaeta / Doutor

Yes / The shortage of fresh water resources is a global problem which requires a prompt solution. Thus, the multi effect distillation (MED) was successfully used for the production of fresh water from seawater. Despite the use of MED desalination system extensively, the influence of the number of effects on the fresh water production cost has not been covered in the open literature. Thus, this paper tries to rectify this specific challenge via simulation at given operating conditions of seawater salinity and temperature. The study is performed using a detailed mathematical model contains the suitable cost correlations. gPROMS model builder suite has been used to carry out an extensive simulation. The results of the study show that the lowest fresh water production cost can be achieved at an optimal number of effects of 17 for a certain operating conditions.

The control of excessive water production in oil and gas producing wells is of increasing importance to the field operator, primarily when trying to maintain the survivability of a mature field from shut in. During the last two decades many chemicals have been studied and applied under the name of relative permeability modifier (RPM) to combat this problem. These chemicals were mostly bullheaded individually into the affected zones, consequently their application resulted in low to medium success, particularly in treating reservoirs suffering from matrix flow. It has been found that the disproportionate permeability reduction depends on the amount of polymer dispersed or absorbed by the porous rock. If single polymers are employed to treat excessive water production in a matrix reservoir they cannot penetrate deep into the formation rock because the polymer will start to build as a layer on the surface of the rock grains. As a result the placement of polymer into the formation will no be piston like and the dispersion over the rock pores will be uneven. To improve water shutoff technology a method of injecting chemicals sequentially is recommended provided that the chemical’s viscosity is increasing successively with the chemicals injected. / Experimentally confirmed, injecting chemicals sequentially provides better results for conformance control. The value of post treatment water mobility is conspicuously lowered by the method of applying injecting chemicals sequentially in comparison with the single chemical injection method. For instance, the residual resistance factor to water (Frrw) at the first cycle of brine flushing for this method is approximately five times higher than the Frrw obtained by injecting only one single chemical. Furthermore, for the second cycle of brine flushing Frrw is still higher by a ratio of about 2.5. In addition to this improvement residual resistance factor to oil Frro for this method is less than two which has been considered as the upper limit for conformance control in matrix reservoir. Accordingly injecting chemical sequentially can be applied for enhancing relative permeability modifier performance in matrix reservoir.