RO Model Research Articles

Sinian-Ordovician Hydrocarbon-source Rock Correlation and Hydrocarbon-generation Evolution in Central and Southeastern Sichuan, China

Abstract: Geology, stratigraphy, drilling, logging, biomarker studies and apatite fission tracks were used to study Sinian-Ordovician mudstone and reservoir bitumen extracted from exploration wells located in central and southeastern Sichuan. This analysis confirms the source rocks were located in a reducing sedimentary environment, with organic matter such as bacteria and algae. The bitumen found in Sinian-Ordovician reservoirs in central Sichuan and Sinian reservoirs in southeastern Sichuan were mostly derived from Cambrian mudstones. The reservoir bitumen found in Cambrian rocks in southeastern Sichuan are from a mixed Cambrian-Silurian source. The apatite fission track combined with the Easy% Ro model were used to reconstruct the hydrocarbon-generation history of Cambrian source rocks in the Dingshan 1 well in southeastern Sichuan. The comparison between the Gaoke 1 well located in central Sichuan and the Dingshan 1 well demonstrates the maturation time and oil and gas generation stage from Cambrian source rocks in southeastern Sichuan is younger than the source rocks from central Sichuan. The source rock formations underwent tectonic uplift and reburial for secondary hydrocarbon-generation. The research methods provided can assist in oil exploration of deep and old hydrocarbon-bearing strata with a multi-stage evolution and tectonically superimposed features in the Chinese Qinghai-Tibet plateau basin, or similar basins worldwide.

MESOZOIC THERMAL EVENTS IN CENTRAL LOWER YANGTZE AREA AND IMPACTS ON HYDROCARBON GENERATION OF MARINE SOURCE ROCKS

AbstractTemperature is a key parameter of controlling hydrocarbon generation of source rocks. Elevated temperature resulted from tectonothermal events may significantly affect hydrocarbon generation. Based on geology, fission track analysis, apatite U‐Th/He and volcanic rock isotopic age data, it is found that there existed Indosinian (T3‐J2) and Yanshanian (J3‐K1) tectonothermal events in Lower Yangtze area and the sedimentary basins reached their peak heat flow at about 130∼110 Ma. The maximum heat flows obtained from thermal history reconstruction based on vitrinite reflectance are ∼94 mW·m–2 and ∼78 mW·m–2 in Jurong and Taixing areas respectively, with an increasing trend from east to west. Hydrocarbon generation history reconstruction based on the EASY%Ro model shows that the dominating gas generation periods of the Cambrian source rock are the Early Permian‐Late Triassic and the Late Triassic‐Early Cretaceous in Changzhou and Jurong areas respectively. Because of the dual effects from the foreland sediments deposited in T3‐J1–2 and the magmatism thermal event in the Early Cretaceous, the marine source rocks reached their maximum temperature at the end of Early Cretaceous. The temperature of the marine source rocks was no longer elevated owing to the decreased heat flow since the Late Cretaceous, though, in some parts of the Jurong, Taixing and Changzhou areas, subsidence occurred and burial depth increased during the K2‐E period. Therefore, the secondary hydrocarbon generation of the marine source rocks is not a widespread process in central Lower Yangtze area.

Modeling, simulation and performance evaluation of a community scale PVRO water desalination system operated by fixed and tracking PV panels: A case study for Dhahran city, Saudi Arabia

In this work complete analytical modeling, simulation with experimental verification of photovoltaic system driving reverse osmosis water desalination is presented. In photovoltaic system, solar radiation and PV generation modeling is done and investigation of the effect of fixed and tracking PV panel on the collected insolation and PV power is carried out. In the RO section, complete model of RO membrane is developed that estimates the feed water pressure and permeate flow rate. The developed PV and RO models are validated individually as well as integrated (combined PVRO) by experimental data and show good agreement. By using this validated model the effect of slope and azimuth angle of the PV panel is studied on the permeate flow rate for the whole year. The increments in the clean water flow rate for the yearly tilt, monthly tilt, single and double axis tracking PV panels with respect to traditional flat panel is computed. The estimated results reveal that yearly optimal tilt angle of PV panels due south is close to the 0.913 times latitude of the Dhahran city. Yearly permeate gain with the yearly optimal tilt, monthly optimal tilt of PV panel relative to flat panel installation is 10% and 19% respectively. The optimization of photovoltaic system suggests the adjustment of the PV orientation (tilt angle and azimuth angle) by using a single and dual axis tracking system installations. The yearly permeate gain made by single and double axis continuous tracking PV panels is 43% and 62% respectively. • The detailed and comprehensive modeling of PVRO system is carried out and validated experimentally. • The validated PVRO model is used for permeate prediction with different fixed and tracked PV panels. • The yearly permeate gain made by single axe PV panels is 43% as compared to the flat PV panel PVRO. • The yearly permeate gain made by double axis tracking PV panels is 62% as compared to the flat PV panel PVRO.

Numerical approach for thermal history modelling in multi-episodic rifting basins

Pre-existing models for thermal history modelling have shown deficiency in explicit algorithms to establish the quantitative relationship between maturity indices and thermal gradients in some sedimentary basins that experienced multi-episodic rifting evolution. In this study, a forward and inverse combination model (FICM) is proposed to estimate the vitrinite reflectance (Ro) and thermal gradients. The forward module is used to calculate Ro values. It couples the EASY%Ro model with burial history reconstruction with consideration of thermal gradient variations during basin evolution. The inverse module reconstructs histoical thermal gradients by calibrating cmputed Ro against measured Ro data. The time-temperature series is a necessary input for both forward and inverse modules. Sample density is a profound factor influencing the accuracy of modelling results. In order to obtain satisfying outputs, a sufficient sample density is required. Thermal gradients are assumed to vary linearly between two given samples. Modelling results of case studies indicate that the sensitivity of heating time to Ro evlution is differnt with thermal gradients depending on geolgoical setting. Three difffernt districts, which include the time-sensitive area, the temperature-sensitive area and the non-sensitive area, can be recognized on the the relationship map among Ro variations, heating time and geothermal gradients. This model can be applied to reconstruct the thermal history and maturation evolution in a basin that has undergone complex multi-episodic rifting.

Source rock evaluation of some upper and lower Cretaceous sequences, West Beni Suef Concession, Western Desert, Egypt

West Beni Suef Concession is located at the western part of Beni Suef Basin which is a relatively under-explored basin and lies about 150km south of Cairo. The major goal of this study is to evaluate the source rock by using different techniques as Rock-Eval pyrolysis, Vitrinite reflectance (%Ro), and well log data of some Cretaceous sequences including Abu Roash (E, F and G members), Kharita and Betty formations. The BasinMod 1D program is used in this study to construct the burial history and calculate the levels of thermal maturity of the Fayoum-1X well based on calibration of measured %Ro and Tmax against calculated %Ro model. The calculated Total Organic Carbon (TOC) content from well log data compared with the measured TOC from the Rock-Eval pyrolysis in Fayoum-1X well is shown to match against the shale source rock but gives high values against the limestone source rock. For that, a new model is derived from well log data to calculate accurately the TOC content against the limestone source rock in the study area. The organic matter existing in Abu Roash (F member) is fair to excellent and capable of generating a significant amount of hydrocarbons (oil prone) produced from (mixed type I/II) kerogen. The generation potential of kerogen in Abu Roash (E and G members) and Betty formations is ranging from poor to fair, and generating hydrocarbons of oil and gas prone (mixed type II/III) kerogen. Eventually, kerogen (type III) of Kharita Formation has poor to very good generation potential and mainly produces gas. Thermal maturation of the measured %Ro, calculated %Ro model, Tmax and Production index (PI) indicates that Abu Roash (F member) exciting in the onset of oil generation, whereas Abu Roash (E and G members), Kharita and Betty formations entered the peak of oil generation.

Modelling of Thermal Effects of Igneous Intrusions on the Temperature Field and Organic Maturity in the Changchang Sag, Qiongdongnan Basin, South China Sea

AbstractThe latest seismic interpretation suggests the presence of several igneous intrusions in the Changchang sag, Qiongdongnan basin, South China Sea. A 2D geothermal modeling based on the finite element method (FEM) is performed to analyze the thermal effects of three intrusions of different scales distributed in the same seismic line. A quantitative evaluation is made on the organic maturity change for the Yacheng Formation caused by intrusions in artificial wells 2 km and 5 km away from each igneous body in combination with the acquired paleo‐geothermal field and the Easy%Ro model. The results indicate that the temperatures of igneous bodies dropped down rapidly during the first 1 Ma after the intrusion and lowered to the nearly same values as that of the wall rock after 10 Ma. The biggest intrusion caused a theoretical vitrinite reflectance (Ro) 1.6% higher than normal for the Yacheng Formation at the place 2 km away and only 0.4% higher for that 5 km distant.

Late-stage Hydrocarbon Accumulation and Enrichment Pattern in Liaozhong Sag, Northern Offshore Bohai Bay Basin

The Liaozhong Sag is one of the major oil-bearing areas in offshore Bohai Bay Basin and is obviously characterized by late-stage hydrocarbon accumulation. In this paper our study was focused on strong activities of tectonic movement in the Liaozhong sag. In terms of source rock thermal history analysis, generation, migration and accumulation of hydrocarbon, late-stage hydrocarbon accumulation and enrichment pattern were summarized. Apatite fission track analysis and evolutionary history of the Easy% Ro model simulation of source rock showed that major source rocks became matured rapidly at the time 5.1Ma from the present. Fault analysis, showed that hydrocarbon migration in the study area was mainly the result of fault transportation. Fluid inclusions indicated that the accumulation period of oil and gas reservoirs was 5.1Ma from the present. Our study showed that late-stage rapid hydrocarbon generation, late-stage vertical fault transportation, hydrocarbon accumulation near source rocks and late-stage rapid in-filling are the main features of hydrocarbon accumulation in the Liaozhong Sag. The abnormal high pressure and fluid inclusion homogenization temperature anomaly are indications of late-stage episodic reservoiring and in-filling. Regional reservoir-cap rock combination of Eocene Shahejie Formation and Oligocene Dongying Formation, predominant transport channels and relevant traps formed by the complex tectonic movement of the Tan-Lu Fault are major factors controlling hydrocarbon accumulation. Episodic reservoiring of formation overpressure, near-source accumulation and fault control constitute the oil and gas enrichment pattern of the Liaozhong Sag.

Numerical modeling of thermal evolution in the contact aureole of a 0.9 m thick dolerite dike in the Jurassic siltstone section from Isle of Skye, Scotland

In this study, we present a heat-transfer-model analysis of thermal evolution in the contact aureole of a 0.9 m thick dolerite dike in the Jurassic siltstone section from Isle of Skye, Scotland based on the constraints from the two types of vitrinite-reflectance geothermometers as well as geochemistry and burial history of host rocks. The predictions from the heat conduction models assuming the finite-time magma intrusion mechanism and pore-water volatilization can match well with both measured vitrinite reflectances and geological conditions of the host rocks. In the region where pore water volatilized and vitrinite reflectance rises with decreasing distance to the dike contact, the bomb geothermometer is consistent with the EASY%Ro model in validating the thermal evolution history of the host rocks, whereas it loses the function of temperature indicator out of the volatilization region. Possibly, the pore-water volatilization influenced the reliability of the bomb geothermometer. The computed total organic carbon contents based on the reconstructed thermal evolution history and the EASY%Ro model present the general agreement with the measured values, demonstrating the availability of the EASY%Ro model in indicating organic-matter transformation ratios at contact metamorphic conditions. ► Volatilization & finite-time intrusion mechanism represent natural conditions. ► Bomb geothermometer is reliable to estimate peak temperature in boiling zone. ► It is consistent with EASY%Ro to calibrate thermal history in boiling zone. ► Reliability of EASY%Ro model at contact metamorphic conditions is verified. ► Estimated TOC based on EASY%Ro model presents good agreement with measurement.

Modeling the Control of Trypanosomiasis Using Trypanocides or Insecticide-Treated Livestock

BackgroundIn Uganda, Rhodesian sleeping sickness, caused by Trypanosoma brucei rhodesiense, and animal trypanosomiasis caused by T. vivax and T. congolense, are being controlled by treating cattle with trypanocides and/or insecticides. We used a mathematical model to identify treatment coverages required to break transmission when host populations consisted of various proportions of wild and domestic mammals, and reptiles.Methodology/Principal FindingsAn Ro model for trypanosomiasis was generalized to allow tsetse to feed off multiple host species. Assuming populations of cattle and humans only, pre-intervention Ro values for T. vivax, T. congolense, and T. brucei were 388, 64 and 3, respectively. Treating cattle with trypanocides reduced R 0 for T. brucei to <1 if >65% of cattle were treated, vs 100% coverage necessary for T. vivax and T. congolense. The presence of wild mammalian hosts increased the coverage required and made control of T. vivax and T. congolense impossible. When tsetse fed only on cattle or humans, R 0 for T. brucei was <1 if 20% of cattle were treated with insecticide, compared to 55% for T. congolense. If wild mammalian hosts were also present, control of the two species was impossible if proportions of non-human bloodmeals from cattle were <40% or <70%, respectively. R 0 was <1 for T. vivax only when insecticide treatment led to reductions in the tsetse population. Under such circumstances R 0<1 for T. brucei and T. congolense if cattle make up 30% and 55%, respectively of the non-human tsetse bloodmeals, as long as all cattle are treated with insecticide.Conclusions/SignificanceIn settled areas of Uganda with few wild hosts, control of Rhodesian sleeping sickness is likely to be much more effectively controlled by treating cattle with insecticide than with trypanocides.

Comparable study on the effect of errors and uncertainties of heat transfer models on quantitative evaluation of thermal alteration in contact metamorphic aureoles: Thermophysical parameters, intrusion mechanism, pore-water volatilization and mathematical equations

Abstract By using a 15 m thick, well-dated basic sill as an example, this study presents an investigation on the effect of errors in thermophysical parameters of igneous intrusions and over-simplification in heat transfer equations as well as uncertainties in pore-water volatilization and intrusion mechanisms of magma on quantitative evaluation of thermal alteration in contact metamorphic aureoles based on heat transfer models and the EASY%Ro model. Our results indicate: 1) Using an under-estimated and temperature-independent specific heat (e.g. ~ 800 J kg− 1 °C− 1) of igneous intrusions instead of the temperature-dependent specific heat can cause the maximum deviation of 68 °C in peak temperature and of 1.3% in vitrinite reflectance, whereas such deviations (less than 26 °C and 0.1%) are small enough to be ignored for the model using a high, invariable specific heat (e.g. ~ 1200 J kg− 1 °C− 1) of igneous intrusions. The specific heat of igneous intrusions is likely a more notable error source in causing model deviations compared to the intrusion temperature and the latent crystallization heat of melted magma, if the latent crystallization heat is allowed for; 2) the effect of the uncertainty in whether pore water volatilized during cooling of intrusive magma on the model prediction can be as notable as that of the use of an under-estimated specific heat. The over-simplification in heat transfer equations (i.e. the variation of thermal conductivity with spatial location is not used) results in an obvious underestimation of the thermal effect of igneous intrusions on host rocks. The model deviation caused by this type of error may be far beyond that caused by the errors in thermophysical parameters of igneous intrusions or the uncertainty in pore-water volatilization; 3) the model deviations due to the errors in the thermophysical parameters and the uncertainty in pore-water volatilization can be large enough to disturb the estimation of the intrusion mechanism based on heat transfer models. By comparing the vitrinite reflectance predicted by different heat transfer models with the measured one, the results from more than one type of model can be found to match well with the observation. Only the model of the finite-time intrusion mechanism can be reasonably regarded as representing natural conditions. It is not fully reliable to validate the availability of the used heat transfer models only by observing whether the model results match with measured geothermometers due to the effect of these uncertainties, errors and over-simplification. More careful model specification and parameter estimation are required in the future use of heat transfer models of igneous intrusions.

A Scalable ID-based Constant-round AGKE Protocol with Logarithmic Computation Complexity

Group key establishment is one of the basic building blocks in securing group communication. In this paper, motivated by Desmedt's BD-II protocol, we propose a secure ID-Based group key establishment protocol which has a constant number of rounds and requires only computation and communication. Our scheme achieves key negotiate by scalar multiplication other than using pairing computation which requires expensive computation cost. Moreover, we have adapted aggregate signature technique verifying the validity of transcripts simultaneously, which greatly improves the computational efficiency. We have proved the security of protocol under the intractability of DDH problem in the RO model.

Security of Cryptosystems Using Merkle-Damgard in the Random Oracle Model

Since the Merkle-Damgard hash function (denoted by MDFH) that uses a fixed input length random oracle as a compression function is not indifferentiable from a random oracle (denoted by RO) due to the extension attack, there is no guarantee for the security of cryptosystems, which are secure in the RO model, when RO is instantiated with MDHF. This fact motivates us to establish a criteria methodology for confirming cryptosystems security when RO is instantiated with MDHF. In this paper, we confirm cryptosystems security by using the following approach: 1. Find a weakened random oracle (denoted by WRO) which leaks values needed to realize the extension attack. 2. Prove that MDHF is indifferentiable from WRO. 3. Prove cryptosystems security in the WRO model. The indifferentiability framework of Maurer, Renner and Holenstein guarantees that we can securely use the cryptosystem when WRO is instantiated with MDHF. Thus we concentrate on such finding WRO. We propose Traceable Random Oracle (denoted by TRO) which leaks values enough to permit the extension attack. By using TRO, we can easily confirm the security of OAEP encryption scheme and variants of OAEP encryption scheme. However, there are several practical cryptosystems whose security cannot be confirmed by TRO (e.g. RSA-KEM). This is because TRO leaks values that are irrelevant to the extension attack. Therefore, we propose another WRO, Extension Attack Simulatable Random Oracle (denoted by ERO), which leaks just the value needed for the extension attack. Fortunately, ERO is necessary and sufficient to confirm the security of cryptosystems under MDHF. This means that the security of any cryptosystem under MDHF is equivalent to that under the ERO model. We prove that RSA-KEM is secure in the ERO model.

Influence of the temperature dependence of thermal parameters of heat conduction models on the reconstruction of thermal history of igneous-intrusion-bearing basins

Heat conduction models are important tools for reconstructing the thermal history of sedimentary basins affected by magmatic intrusions. Accurate thermal properties of the intrusion and its wall rocks are crucial for accurate predictions of thermal history. Although data on the thermal properties of rocks used in the models are not yet sufficient, we theoretically evaluated the influence of their temperature dependence on the reconstruction of the thermal history of wall rocks of a cooling intrusive sheet. In this study, due to their relatively adequate thermophysical data over wide temperature ranges, diabase, limestone, and Berea sandstone are assumed as the intrusion and the wall rocks in a heat conduction model. A linear interpolation algorithm is used to fit the temperature dependence of their thermal conductivity and specific heat based on experimental data. Simulations indicate that (a) the temperature dependence of these thermal properties can improve the estimation of the contact temperature ( Tc), (b) the deviation of Tc from a temperature-independent-coefficient heat conduction model can be as large as 102 °C for limestone and 61 °C for Berea sandstone, and (c) this is also the maximum deviation in the peak-temperature profile of wall rocks. However, its effect on the peak-temperature profile of wall rocks which is above 20 °C only occurs in a very narrow zone that is less than a half width of the intrusion away from the contact or a domain with the peak temperature above 500 °C. Furthermore, the temperature dependence can also significantly change the thermal-evolution history of wall rocks, lowering the cooling rate of magma intrusion and hence influencing the prediction of vitrinite reflectance ( Ro) based on the EASY%Ro model. Until a magma intrusion almost completely cools down, the maximum deviation in the predicted Ro profile of wall rocks from the temperature-independent-parameter heat conduction model can attain 0.47% for Berea sandstone at a location of about 150% of the intrusion width away from the contact and 0.62% for limestone at a location of about 92% of this distance.

Online Public Key Cryptographic Scheme For Data Security In Bridge Health Monitoring

Abstract the paper proposes an online-public-key cryptographic scheme for data security in bridge health monitoring. The scheme solves the problem such as how to preserve and manipulate the users’ private key securely. Meanwhile, it realizes the mutual authentication between user and server, in which the private key splitting method is proven to be secure in the RO model. The analysis shows that the scheme is able to resist the normal attacks such as the denial of service or the off-line password guess effectively. It has strong robustness in applications.

Characteristics and oleocellosis sensitivity of citrus fruits

The effects of variety, growth phase, and water loss on development of oleocellosis, and relationships between chromatism and Vis/NIR spectra were studied in ‘EarlyGold’ sweet orange ( Citrus sinensis Osbeck), ‘Fukumoto’ navel ( Citrus sinensis Osbeck), and ‘Cara Cara’ navel ( Citrus sinensis Osbeck) oranges. The varieties showed significant differences in the rate (RO) and degree (DO) of oleocellosis development. The sensitivity of varieties (from most to least sensitive) was ‘EarlyGold’ > ‘Fukumoto’ > ‘Cara Cara.’ Growth phase and water loss had a significant influence on fruit sensitivity to oleocellosis. The order of sensitivity to oleocellosis was dependent on harvest time (i.e., at normal period > at delayed period > at uncolored period), and RO and DO decreased significantly with water loss. The RO and DO models for fruit water loss were established as y = 0.75 − 3.94 x − 271.33 x 2 ( R 2 = 0.77) and y = 1.70 − 7.29 x − 1025.83 x 2 ( R 2 = 0.583). The sensitivity of ‘EarlyGold’ to oleocellosis was significantly correlated with d L and d C of fruit chromatism. At the same time, there were significant differences at 480–575 nm, 650–720 nm, and 925–965 nm between varieties with low and high sensitivity to oleocellosis, and ‘EarlyGolds’ with a low RO and DO had a higher reflectance than those with a high RO and DO.

Thermal decomposition of natural fibers: Global kinetic modeling with nonisothermal thermogravimetric analysis

AbstractThe modeling of thermal decomposition process of ten natural fibers commonly used in polymer composite industry was performed by assuming a global model occurring within the entire degradation range with consideration of fiber as one pseudocomponent. Málek method with activation energy values previously obtained was applied to the modeling process. Careful calculation and evaluation indicated that, within an acceptable error limit of 5%, RO(n &gt; 1) model can be used to describe the degradation process of most selected fibers well. The other kinetic parameters used include activation energy range of 160–170 kJ/mol; parameter n in RO(n &gt; 1) = (1 − α)n of 3–4; and ln A between 35 and 42 ln s−1. Some condition limitations of the obtained model were also discussed. The model has practical significance in predicting fiber weight loss when the fiber is used in combination with engineering thermoplastics. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Investigations on Simultaneously Secure IBE Scheme and Security Proofs under RO and Non-RO Model

This paper analyses security mechanism and authentication, key agreement protocol of 3G system amply, puts forward a amelioration scheme. This scheme assures security communications without credible VLR. This paper analyses ameliorative protocol and resolves the security communications problem between MS and HLR.

THE THERMAL GRADIENT HISTORY OF THE THRACE BASIN, NW TURKEY: CORRELATION WITH BASIN EVOLUTION PROCESSES

Thermal maturity modelling is widely used in basin modelling to help assess the exploration risk. Of the calibration algorithms available, the Easy%Ro model has gained wide acceptance. In this study, thermal gradients at 70 wells in the Thrace Basin, NW Turkey, were calibrated against vitrinite reflectance (%Ro) using the Easy%Ro model combined with an inverse scheme. The mean squared residual (MSR) was used as a quantitative measure of mismatch between the modelled and measured %Ro. A 90% confidence interval was constructed on the mean of squared residuals to assess uncertainty. The best thermal gradient (i.e. minimum MSR) was obtained from the MSR curve for each well, and an average palaeo‐thermal gradient map of the Thrace Basin was therefore created. Calculated thermal gradients were compared to the results of previous studies. A comparison of modelled palaeo‐thermal gradients with those measured at the present day showed that the thermal regime of the Thrace Basin has not changed significantly during the basin's history.The geological and thermal characteristics of the Thrace Basin were compared and the thermal anomalies were evaluated as a function of basin evolution processes. The basin's thermal regime was controlled by: (1) basement edge effects; (2) crustal thickness and basement heat flows; (3) thermal conductivity variations within the stratigraphic column; (4) transient heat flow effects; and (5) the influence of tectonic features. The impact of these factors on variations in the thermal gradients is discussed in detail.Basement edge effects are most marked on the steep northern margin of the basin where heat is preferentially retained in highly conductive basement rocks rather than being transferred into less conductive sedimentary rocks. Thus, heat is significantly focused onto the northern edge of the basement, resulting in a thermal anomaly along the northern basin margin.The margins of the basin, with relatively thick upper crust, have relatively higher thermal gradients compared to the central areas. This is due to radiogenic heat production in the upper crust. Thus, thermal gradients increase above highs and at the margins where thicker upper crust is present. A heat flow map of the Thrace Basin, constructed using a basin‐scale crustal thickness map and a basement heat‐flow algorithm, is presented and demonstrates the heat generation potential of the upper crust.The Eocene Ceylan Formation, which has relatively low thermal conductivity, significantly reduces the thermal gradients by blocking heat transferred from the basement. Areas of high sedimentation rate are associated with low thermal gradients due to the transient heat flow effects of young, thick and “thermally immature” sediments as a function of the heat capacities of these deposits.A direct relationship between thermal gradients and major structural trends could not be established because of a number of factors including the inactivity of the subsurface Miocene fault systems, which did not allow the flow of high temperature fluids through to shallow depths; also, the steady burial and sedimentation rates since the Early Eocene have maintained the pressure system in equilibrium.

A METHOD FOR ANALYZING GEOTHERMAL GRADIENT HISTORIES USING THE STATISTICAL ASSESSMENT OF UNCERTAINTIES IN MATURITY MODELS

A major factor contributing to uncertainty in basin modelling is the determination of the parameters necessary to reconstruct the basin's thermal history. Thermal maturity modelling is widely used in basin modelling for assessing the exploration risk. Of the available models, the chemical kinetic model Easy%Ro has gained wide acceptance.In this study, the thermal gradient at five wells in the Danish North Sea is calibrated against vitrinite reflectance using the Easy%Ro model coupled with an inverse scheme in order to perform sensitivity analysis and to assess the uncertainty. The mean squared residual (MSR) is used as a quantitative measure of mismatch between the modelled and measured reflectance values. A 90% confidence interval is constructed for the determined mean of the squared residuals to assess the uncertainty for the given level of confidence. The sensitivity of the Easy%Ro model to variations in the thermal gradient is investigated using the uncertainty associated with scatter in the calibration data. The best thermal gradient (minimum MSR) is obtained from the MSR curve for each well. The aim is to show how the reconstruction of the thermal gradient is related to the control data and the applied model.The applied method helps not only to determine the average thermal gradient history of a basin, but also helps to investigate the quality of the calibration data and provides a quick assessment of the uncertainty and sensitivity of any parameter in a forward deterministic model.

An experimental study of global loads acting on an intact and damaged Ro–Ro ship model

Measurements of global loads acting on a Ro–Ro model have been carried out in regular waves for intact and damaged conditions. The stationary model was tested in different wave heights and wave frequencies for the head, beam and stern quartering seas in order to explore the effect of damage and wave heights on the global loads acting on the model. The analysis of the results indicates that damage has an adverse effect on the structural loading responses of the model depending upon the directionality of the waves and frequency range applied. This effect may cause structural damage on the ship and danger the safety of the ship and passengers on board.