Initial Production Phase Research Articles

Metagenome-assembled genomes provide insight into the metabolic potential during early production of Hydraulic Fracturing Test Site 2 in the Delaware Basin.

Demand for natural gas continues to climb in the United States, having reached a record monthly high of 104.9 billion cubic feet per day (Bcf/d) in November 2023. Hydraulic fracturing, a technique used to extract natural gas and oil from deep underground reservoirs, involves injecting large volumes of fluid, proppant, and chemical additives into shale units. This is followed by a "shut-in" period, during which the fracture fluid remains pressurized in the well for several weeks. The microbial processes that occur within the reservoir during this shut-in period are not well understood; yet, these reactions may significantly impact the structural integrity and overall recovery of oil and gas from the well. To shed light on this critical phase, we conducted an analysis of both pre-shut-in material alongside production fluid collected throughout the initial production phase at the Hydraulic Fracturing Test Site 2 (HFTS 2) located in the prolific Wolfcamp formation within the Permian Delaware Basin of west Texas, USA. Specifically, we aimed to assess the microbial ecology and functional potential of the microbial community during this crucial time frame. Prior analysis of 16S rRNA sequencing data through the first 35 days of production revealed a strong selection for a Clostridia species corresponding to a significant decrease in microbial diversity. Here, we performed a metagenomic analysis of produced water sampled on Day 33 of production. This analysis yielded three high-quality metagenome-assembled genomes (MAGs), one of which was a Clostridia draft genome closely related to the recently classified Petromonas tenebris. This draft genome likely represents the dominant Clostridia species observed in our 16S rRNA profile. Annotation of the MAGs revealed the presence of genes involved in critical metabolic processes, including thiosulfate reduction, mixed acid fermentation, and biofilm formation. These findings suggest that this microbial community has the potential to contribute to well souring, biocorrosion, and biofouling within the reservoir. Our research provides unique insights into the early stages of production in one of the most prolific unconventional plays in the United States, with important implications for well management and energy recovery.

A Comprehensive Investigation of the Relationship between Fractures and Oil Production in a Giant Fractured Carbonate Field

This study examines the connections between various fracture indicators and production data with an example from one of the giant fields in the Middle East producing complex fractured carbonate lithologies. The field under study hosts two reservoirs with a long development and production history, including carbonates from the Asmari and Bangestan Formations. A fracture intensity map was generated based on the interpretation of image logs from 28 wells drilled within the field. Mud loss data were collected and mapped based on the geostatistical Gaussian Random Function Simulation (GRFS) algorithm. Maximum curvature maps were generated based on Asmari structural surface maps. Comparing the results shows a good agreement between the curvature map, fault distribution model, mud loss map, fracture intensity map, and productivity index. The results of image log interpretations led to the identification of four classes of open fractures, including major open fractures, medium open fractures, minor open fractures, and hairline fractures. Using the azimuth and dip data of the four fracture sets mentioned above, the fracture intensity log was generated as a continuous log for each well with available image log data. For this purpose, the fracture intensity log and a continuous fracture network (CFN) model were generated. The continuous fracture network model was used to generate a 3D discrete fracture network (DFN) for the Asmari Formation. Finally, a 3D upscaled model of fracture dip and azimuth, fracture porosity, fracture permeability, fracture length, fracture aperture, and the sigma parameter (the connectivity index between matrix and fracture) were obtained. The results of this study can illuminate the modeling of intricate reservoirs and the associated production challenges, providing insights not only during the initial production phase but also in the application of advanced oil recovery methods, such as thermal recovery.

Pumpkin seed flour (Cucurbita pepo l.) as an alternative source in the feeding of pigs in the initial phase of production

Food production in a sustainable way is based on the association between animals and vegetables to minimize costs, environmental impact, and the use of insums in the breeding process. The objective of this work was to evaluate the effect of the inclusion of pumpkin seed flour (Cucurbita pepo L.) in the diet on the performance of early-stage pigs and the reduction of endoparasites in a commercial rearing system. The experimental design was completely randomized, with three treatments and six replicates, and the experimental unit consisted of two animals, totaling 36 animals. The treatments were the basal diet and two levels of inclusion of pumpkin seed: 5 and 10%. The animals were of the Agroceres line, with 42 days of age and an average weight of 12 kg. The animals and rations were weighed at the beginning and at the end of the 35-day experimental period to obtain the performance variables. A bromatological analysis was performed to evaluate the composition of pumpkin seed and for parasitic analysis, feces were collected individually from the animal. There was no significant effect for the Tukey test at the level of 5% probability, of the inclusion of pumpkin seed flour on in the parameters of weight gain and feed conversion. Was observed the reduction of helminth eggs present in feces using egg count and oocysts per gram of feces (OPG), performed at the beginning and end of the experiment. It is indicated the inclusion of 10% of pumpkin flour in the feeding of pigs in the initial phase by reducing contamination by verminosis and does not alter animal performance.

Vegetable lipid sources in the diet of japanese quails in the rearing phase and effects on the initial phase of production

Resumo A pesquisa foi conduzida com objetivo de avaliar o efeito residual de diferentes fontes lipídicas na dieta de codornas japonesas (Coturnix japonica) na fase de recria sob o desempenho e a qualidade de ovos na fase inicial de postura. Na primeira etapa foram utilizadas 400 codornas japonesas com idade de 21 dias, as aves foram distribuídas em tratamentos seguindo um delineamento inteiramente casualizado com dez repetições, de oito aves, em cinco tratamentos: ração basal (RB) com 2,5% de óleo de soja, RB com 2,5 % de óleo de milho, RB com 2,5% de óleo algodão, RB com 2,5% de óleo de girassol e RB com 2,5% de óleo de canola. Aos 42 dias mantendo o delineamento inicial, todas aves receberam ração basal com óleo de soja, para que fosse avaliado o efeito residual da fase anterior sobre o desempenho e a qualidade dos ovos na fase inicial de postura (43 - 84 dias). As diferentes fontes lipídicas não afetaram o desempenho das aves na fase inicial de produção. Para a qualidade dos ovos, os parâmetros de altura, diâmetro e índice de gema, gravidade e UH foram melhores no tratamento com utilização de óleo de girassol. Houve efeito residual da utilização de fontes lipídicas de origem vegetal na dieta em fase de recria de codornas japonesas sobre as características da qualidade dos ovos. As fontes lipídicas oriundas das sementes de soja, milho, algodão, canola e girassol podem ser utilizadas como ingredientes energéticos na dieta de recria de codornas poedeiras por nâo serem prejudiciais ao desempenho inicial das aves. A longevidade na produção dos ovos das aves alimentadas com diferentes fontes lipídicas na fase de recria foi semelhante.

Fontes lipídicas vegetais na alimentação de codornas japonesas em fase de recria e sua repercussão na fase inicial de produção

Abstract This study aims to evaluate the residual effect of different lipid sources in the diet of Japanese quails (Coturnix japonica) in the rearing phase on the performance and egg quality in the initial phase of egg-laying. In the first stage, 400 Japanese quails aged 21 days were used, being distributed in a completely randomized experimental design, with five treatments and ten replicates of eight birds/replicate Treatments consisted of basal ration (BR) with 2.5% soybean oil; BR with 2.5% corn oil; BR with 2.5% cottonseed oil; BR with 2.5% sunflower oil; and BR with 2.5% canola oil. At 42 days, maintaining the initial design, all quails received a basal ration with soybean oil, in order to evaluate the residual effect of the previous phase on the performance and egg quality in the initial phase of egg-laying (43 - 84 days). The different lipid sources did not affect the performance of quails in the initial phase of production. For egg quality, yolk height, yolk diameter, yolk index, gravity, and Haugh unit (HU) showed better results in the treatment using sunflower oil. There was a residual effect of the use of lipid sources of vegetable origin in the rearing phase diet of Japanese quails on egg quality traits. Lipid sources from soybean, corn, cottonseed, canola, and sunflower seeds can be used as energy sources in the rearing diet of egg-laying quails for not being harmful to their initial performance. The longevity in egg production of quails fed with different lipid sources in the rearing phase was similar.

Provenance and Production: Casks in the Dutch Archaeological Context

Abstract The Late Medieval and Early Modern periods in the Netherlands are marked by an upsurge in the production, use and repurposing of casks in cities. This is inextricably linked with the growing marine and riverine trade markets and the increase in artisan production. Casks have been found on shipwrecks, where they were used as containers for merchandise (primary purpose) and in urban areas, where they were repurposed as shafts for wells or cesspits (secondary purpose). As a result, the initial production phase of the lifecycle of casks often remained undetected. This study aims to generate an overview of the dendrochronological studies conducted in the past decades by Dutch dendrochronologists on casks from Dutch archaeological context, in which the felling year of the wood used to construct the casks can be dated from the 12th to 18th centuries, to gain insight into their production by coopers. The first objective is to better understand the diverse provenance areas detected in the coopers’ timber, after which the diachronic developments in the use of the timber from specific provenance areas can be addressed. The main objective is to assess whether it is possible to distinguish locally produced casks from casks used to import merchandise, which was successful in some cases. In addition to the dendrochronological and archaeological data, archival sources were used to contextualize and substantiate the analyses and interpretations.

Exploration and Practice of CO2 Huff-N-Puff Combined CO2 Flooding in Shale Oil Well Cluster Group

Shale oil production wells in Dagang Oilfield in China are put into production by means of horizontal well and segmented multi-cluster massive volume fracturing. The production characteristics are that the output is high in the initial phase of production, the output decreases rapidly with the continuous production, and there are no effective measures to increase production. There is an urgent need for stimulation technology to improve the recovery of shale reservoir. In the field of oilfield development, CO2 has multiple advantages such as easy injection, viscosity reduction and energy increase. For the shale oil well cluster group with good inter well connectivity, the author designs an implementation mode of “CO2 huff-n-puff combined CO2 flooding” to improve shale oil production. This implementation mode can play the dual role of CO2 huffn- puff combined CO2 flooding and CO2 drive to realize the efficient production increase of shale oil well group. After two phases of implementation of the test well group, the cumulative oil increase of the well group has reached 3864 tons, and the comprehensive oil change rate has reached 1:1.22, which has achieved good stimulation effect. This implementation method can effectively improve the production of shale oil reservoirs and provide a new technical measure for improving production and efficiency of similar shale reservoirs.

Histopathology and molecular identification of Henneguya pseudoplatystoma

The present study proposes to characterize the parasites isolated during the initial phase of production in fish farms located in Mato Grosso do Sul in the central-western region of Brazil, using histopathology analysis and molecular techniques. A total of 340 hybrid surubim fish (Pseudoplatystoma reticulatum × P. corruscans) from four farms were examined during the co-feeding phase. Histopathology analysis showed that 10.9% (n = 37) of the fish were infected with parasites. Branchitis, lifting epithelium, hypertrophy of epithelial cells, lamellar fusion, aneurisms and infection in the bone tissue of the gill filament was observed. The parasite species was determined by amplification of the 18S rRNA gene followed by sequencing. The phylogenetic analysis of nucleotide sequences indicates a close relationship (99.6%) with Henneguya pseudoplatystoma reported to be infecting the hybrid Pseudoplatystoma. This study demonstrates the occurrence of H. pseudoplatystoma in hybrid surubim (P. reticulatum × P. corruscans) during the co-feeding phase in fish farms in Mato Grosso do Sul. Also, molecular techniques provide a faster and sensitive method to identify fish parasites, and may assist in the development of new management techniques aimed at improving the sanitary conditions contributing to the reduction of mortality rates in these animals.

Model analysis and optimization of operating rates of enterprises with small-series production type

The article deals with issues surrounding the production management of enterprise with small-series production type. Specific features of small-series production are determined. Task complex defined by initial production phase comes under review. Problem of calculation, analysis and optimization of machine load is covered in depth. It is assumed that machine load calculating task will minimize potencial stress of production plan and maximize workplace capacity. Calculations are carried out for each type of work for the required period (year, month, week, etc.) for the whole enterprise, workshops, production areas, workplaces. The labor intensity for each workplace and usage coefficient are calculated. The analysis of obtained indexes is the basis for redistribution of the workload capacity.

Production data analysis of shale gas using fractal model and fuzzy theory: Evaluating fracturing heterogeneity

The development of shale-gas reservoirs has been dramatically accelerated with the technical breakthroughs made in the fields of horizontal well drilling and multistage hydraulic fracturing. After being restructured by hydraulic fracturing, the shale reservoir would have a complicated fracture network featuring great randomness. The accurate evaluation of the fracture network structure and the quantitative calculation of the fracturing fluid flowback are keys to the efficient development of shale-gas fields. In this paper, a new fractal seepage model of single fracturing section was established based on the conversion relationship of gas-liquid flow fractal dimension. Then, the sensitivity of model parameters and the flow characteristics of single fracture section were analyzed to determine the reason that gas production “rises first, and then drops down” at the initial production phase. Finally, the mathematical description of the heterogeneity of fracture networks was further proposed based on Fuzzy theory. Case studies in Fuling shale-gas field were performed by means of the Extended Monte Carlo Simulation and the optimal fracturing heterogeneity factors of typical wells are 0.25, 0.10 and 0.15. Compared with the homogeneous model, the accuracies of gas production and water production calculated by heterogeneous model are increased by up to 15% and 20%, respectively.

Characteristics of Quality Semen, Hatching Arabic Chicken Eggs and Growth of Chicks from Crosses

This study aims to evaluate and analyze the characteristics of the quality of semen, and hatching of Arab chicken eggs and the growth of crosses from chicks. This research was conducted at the Permata Farmer Group business, Wua-wua Village, Wua-wua District Kendari, Southeast Sulawesi for three months. This study uses a Completely Randomized Design which is three treatments and six replications. The parameters measured were semen quality, egg weight, egg index, fertility, DOC weight gain, feed consumption, and feed conversion. The data analysis used is Analysis of Variance. The results of this study indicate that the consequences of crossing three males did not have a significant effect (P> 0.05) on the measured parameters. It can be seen in the research process which gives results that are not much different from the results of the crossing of three different males using the Arabic parent in the initial phase of production.

Improving Megaproject Economics Through the Use of Early Production

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 177729, “Improving Megaproject Economics Through the Use of Early Production,” by James A. Volker and Adam J. Bond, Zakum Development Company, prepared for the 2015 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 9–12 November. The paper has not been peer reviewed. A key aspect of the project discussed in this paper is the use of minimal initial-production facilities to achieve significant early production from each of four preconstructed artificial islands. The initial-production facilities leverage the use of spare processing capacity on existing adjacent satellite platforms to allow for production from each of the islands during the 4-year period between completion of the first wells and completion and startup of the permanent production facilities. Introduction The project is approximately 80 km offshore in the Persian Gulf and consists of four artificial islands. The objective of the initial production phase is to provide early and sustained production from wells drilled on the islands as soon as they are available, thereby achieving advanced revenue generation and improved project economics while the permanent production facilities are under construction. Initial startup was achieved from the first island in November 2014, followed by initial startup of the second island in April 2015. This is the first phase of the plan to increase production from the field by approximately 40%. The project is segmented into an initial- production phase and permanent production buildup phases. The initial-production phase will continue until completion of the first permanent production buildup phase in 2018. The project achieved startup of initial production within 4 years of conceptual design in 2010 and a minimum of 4 years before completion of the permanent production facilities, thereby achieving the goal of capturing the benefits of the initial-production strategy. Benefits and Challenges The initial production strategy evolved and was optimized from conceptual design through front-end engineering and detailed design, resulting in the fit-for-purpose initial-production facilities for the first three islands. Given the short operating duration of the initial-production facilities, cost efficiency was the key driver in decision making. To ensure implementation of only the most cost-effective fit-for- purpose facilities, the early operating experience from the first island was used to simplify further the design of the initial-production facilities on the fourth island.

An Efficiency Planning in Supply Chain Management with Mathematical Programming

Starting from the initial phase of production, suppliers involved in all the processes from consumers to recycling is a whole made up of consumers, producers and distributors. Supplier chain management is an approach that integrates suppliers, producers, distributors and retail sellers in a most efficient way. One of the most important pieces of this whole is supplier chain. Supplier chain should be designed in an integrated manner that will manage the flow of goods and information. In order to boost the long-term performance of the firms in the supplier chain, managerial functions and plans should be devised in a systematic and strategic manner. In this study, the problem of the distribution of production plan in supply chain management the effectiveness of planning is discussed. Under the terms of a production deployment of various enterprises, restrictive for mathematical programming problem-based alternative a model has been tried to be developed.

Quantitative characteristics of Atlantic halibut (Hippoglossus hippoglossus L.) egg quality throughout the reproductive season

Assessment of egg quality is an important aspect in finfish hatchery management, but guidelines for such assessment are scarce, especially for marine fish production. In the present work, potential indicators of egg and larval quality were measured in 39 batches of eggs of Atlantic halibut (Hippoglossus hippoglossus L.) throughout the reproductive season. The paternal influence on offspring was minimized by using the same cryopreserved semen for all fertilizations; consequently, maternal effects were emphasized. The progression of the spawning season and ovarian fluid parameters, including pH, electrical conductivity (EC), osmolality, and the amount of fluid were registered. The behavior of the broodfish at egg collection was registered and the eggs were analyzed for cortisol content. Fertilization and hatching rates as well as larvae survival were calculated, and larval standard length and myotome height were measured. Furthermore, the occurrence of major types of larval deformities was registered. The myotome height was significantly (P < 0.05) affected by the spawning season progress. Cortisol content in the eggs was decreasing with the progressing spawning season and correlated positively with the occurrence of yolk-sac edema. The ovarian fluid pH and EC were significantly related to fertilization and hatching rates. High fertilization and hatching success was associated with pH greater than 7.9 and EC less than 2.5 mS/cm. Low fertilization rates (<50%) resulted in further low hatchability from such egg batches. Ovarian fluid EC was significantly and positively related to increased occurrence of yolk-sac edema. High quantity of ovarian fluid in egg batches was associated with reduced egg quality in terms of fertilization and hatching rates and occurrence of yolk-sac edema. A cumulative effect of ovarian fluid pH, EC, osmolality, and quantity explained up to 62% of the total variation in fertilization rates. The findings from the present study indicate that parameters measurable at the initial phase of production, in particular ovarian fluid pH and EC, might have a potential for future use as egg quality indicators in hatchery management.

QFD 및 Stage-gate 모델을 활용한 국방분야 개발단계 품질관리 방안 연구

Purpose: The purpose of this study is to propose adoption of QFD and Stage-gate in order to analyze the quality of korea defense system. Methods: Drawing change data of initial production phase in korea defense system were anlayzed and a practical method was proposed. Results: The results of this study are as follows; Off line Quality Control should be introduced in development phase. Specially, in case of defense system, the best method is QFD(Quality Function Deployment) and Stage-gate process. At first, QFD 1 step defines product planning from VOC(Voice Of Customer), QFD 2 step specifies part planning from product planning, QFD 3 step defines process planning from part planning, QFD 4 step defines production planning from previous process planning. Secondly, Stage-gate process is adopted. This study is proposed 5 stage-gate in case of korea defense development. Gate 1 is located after SFR(System Function Review), Gate 2 is located after PDR(Preliminary Design Review), Gate 3 is located after CDR(Critical Design Review), Gate 4 is located after TRR(Test Readiness Review) and Gate 5 is located before specification documentation submission. Conclusion: Off line QC(Quality Control) in development phase is necessary prior to on line QC(Quality Control) in p roduction phase. For the purpose of off line quality control, QFD(Quality Function Deployment) and Stage-gate process can be adopted.

Effect of different concentrations of metabolisable energy and protein on performance of White Leghorn layers in a tropical climate

1. An experiment was conducted to study the effects of feeding graded concentrations of metabolisable energy (ME) and crude protein (CP) on the performance of layers. Nine diets with three concentrations each of ME (10.04, 10.67 and 11.30 MJ/kg) and CP (150, 165 and 180 g/kg) in a 3 × 3 factorial arrangement of treatments were formulated.2. A total of 5544 White Leghorn (WL) pullets (20 weeks of age) were housed in 4-bird colony cages and 22 adjacent cages constituted a replicate. Each diet was fed ad libitum to 7 replicates from 21 to 72 weeks of age. Production variables were recorded in 13 laying periods of 28 d each, and the data were pooled into three production phases, namely initial (21–32 weeks), peak (33–52 weeks) and post-peak (53–72 weeks).3. No interaction was observed between ME and CP for egg production (EP), food intake (FI), food efficiency (FE), egg weight (EW), egg mass (EM) and body weight gain.4. The EP, EW and EM during the initial phase of production were not affected by dietary ME concentrations, while the EW and EM improved with increasing concentrations of dietary CP from 150 to 165 g/kg.5. During the peak production phase, improvements in EP (ME and CP), FI (ME), FE (ME, CP), EW (ME) and EM (ME, CP) were observed with increasing concentrations of energy and protein to 11.30 and 180 g/kg diet, respectively.6. EP, EW and EM were unaffected by dietary variation in concentrations of ME and CP during post-peak production phase, but the FE improved and FI reduced with increasing dietary concentrations of these nutrients.7. It is concluded that the optimum concentrations of ME for WL layers during the 21–32, 33–52 and 53–72 weeks of age are 11.30, 11.30 and 10.04 MJ/kg diet, respectively. The corresponding values for CP in diets are 180, 180 and 150 g/kg.

CMS users data management service integration and first experiences with its NoSQL data storage

The distributed data analysis workflow in CMS assumes that jobs run in a different location to where their results are finally stored. Typically the user outputs must be transferred from one site to another by a dedicated CMS service, AsyncStageOut. This new service is originally developed to address the inefficiency in using the CMS computing resources when transferring the analysis job outputs, synchronously, once they are produced in the job execution node to the remote site.The AsyncStageOut is designed as a thin application relying only on the NoSQL database (CouchDB) as input and data storage. It has progressed from a limited prototype to a highly adaptable service which manages and monitors the whole user files steps, namely file transfer and publication.The AsyncStageOut is integrated with the Common CMS/Atlas Analysis Framework. It foresees the management of nearly nearly 200k users' files per day of close to 1000 individual users per month with minimal delays, and providing a real time monitoring and reports to users and service operators, while being highly available. The associated data volume represents a new set of challenges in the areas of database scalability and service performance and efficiency. In this paper, we present an overview of the AsyncStageOut model and the integration strategy with the Common Analysis Framework. The motivations for using the NoSQL technology are also presented, as well as data design and the techniques used for efficient indexing and monitoring of the data. We describe deployment model for the high availability and scalability of the service. We also discuss the hardware requirements and the results achieved as they were determined by testing with actual data and realistic loads during the commissioning and the initial production phase with the Common Analysis Framework.

Country- and age-specific optimal allocation of dengue vaccines

Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.

가속수명시험 자료에 감마 과정 모델을 적용한 저장 수명 예측 기법 연구

추진장약의 저장 기간에 따른 안정제 함량의 저하에 관하여 가속수명시험 자료를 활용한 수명 예측 기법을 제시하였다. 결정론적 가속수명시험 및 저장분석 시험자료를 단순회귀분석으로 계산한 수명 예측값은 상태 분포와 수명 분포를 표현할 수 없다. 기존의 연구에서 감마분포를 이용하여 저장분석 시험자료에 대한 상태 분포 및 수명 분포를 보여주고 기대 수명을 계산하는 방법이 제시되었으나, 양산 초기 실제 자료를 수집하는 것이 불가능한 한계를 가지고 있다. 본 연구에서 제시된 예측 방법에 의한 기대 수명은 기존의 연구와 유사한 값을 보이며 상태 분포와 수명 분포를 설명할 수 있고, 유도무기 추진기관의 추진제 또는 부품류의 노화와 관련한 수명 주기 관리에도 활용할 수 있다. This paper presents a method to estimate a storage life for loss of stabilizer content as storage periods using accelerated life test data. The estimate of storage life based on deterministic accelerated life test and degradation data cannot describe a condition distribution and storage life distribution. Previously, the method to show the condition distribution and storage life distribution by using gamma process has been studied. But it has limitation because it is impossible to collect the deterioration data at initial production phase. The estimated storage life presented by this study shows the similar value to previous studies and the method can describe the condition distribution and storage life distribution. So, the estimation method studied in this paper can be used for a life cycle management about deterioration of propellant for propulsion unit or components of missile, too.

Improved UOE Pipe-Manufacturing Process Helps Meet Deepwater Pipeline Challenges

Technology Update Conventional pipeline design, although concerned with many factors, generally centers on the need to withstand the internal pressure in the line. The higher the pressure at which throughput can flow, the higher the flow rate, and the greater the revenue potential for the operator. However, when considering the factors critical for deepwater pipelines, much of the focus shifts to the need to withstand the external pressure on the line, particularly during installation. With local "infield" lines, such as subsea umbilicals, risers, and flowlines, the challenge is modest because the lines are small in diameter and, thus, inherently resistant to hydrostatic collapse. These lines are generally produced as seamless pipe, which in smaller sizes is readily available and generally a suitable economic solution. However, deepwater trunklines, especially with long-distance tiebacks, present a greater challenge. These lines must be wider in diameter to meet the production demands of large-scale, high-cost projects. Thicker pipe wall is required to ensure that pipes can withstand the hydrostatic pressure and bending that affect them as they are laid to the seabed. Often, these are 16- to 20-in.-diameter lines, which places them at the economic limit for seamless pipe production methods. A project table including some typical deepwater pipe properties is shown in Fig. 1. It is possible to produce thick-walled, seamless pipe at these diameters by means of the Pilger process, in which hot round steel billets that have been hollowed in the initial phase of production are rolled and stretched until the desired length and diameter are achieved. However, the manufacturing process is slow and the cost of material high. The most economic method of manufacturing pipe at these wall thicknesses and diameters is the UOE process, in which steel plate is pressed into a U and then an O shape and then is expanded circumferentially. (This process was used in the projects shown in Fig. 1.) The advantages of the UOE process notwithstanding, the current wall-thickness and diameter requirements for deepwater trunkline pipe still have proved challenging from the standpoint of manufacturing economics and installation capabilities. Only a handful of manufacturers are capable of supplying double-submerged, arc-welded (DSAW) pipe that meets specifications for the deepest projects, such as the Shell Perdido development in the Gulf of Mexico. The acceptability of a pipeline design for a given water depth is determined by means of standard equations that measure the relationship between outside diameter, wall thickness, pipe shape, and material compressive strength.