Application of an analytic hierarchy process to hydrocarbon accumulation coefficient estimation

The hydrocarbon accumulation coefficient is a key parameter in resources evaluation by genetic techniques. Methods of obtaining its value scientifically have always been an important factor influencing evaluation credibility. In this paper, the hydrocarbon accumulation system is evaluated quantitatively by establishing a hierarchy structure model based on an analytical hierarchy process. The hydrocarbon accumulation system of a higher exploration degree is selected as a calibration area and its hydrocarbon accumulation coefficient can be calculated using methods of hydrocarbon generation potential and reservoir-scale sequence. The hydrocarbon accumulation coefficient of a petroleum accumulation system can be gained by analogy of reservoir forming comprehensive evaluation results with the calibration area. The hydrocarbon accumulation coefficient of each petroleum accumulation system in the upper reservoir-forming combination of the Liaohe Western Sag can be obtained with this method. Practice shows that using the analytical hierarchy process to quantitatively evaluate the hydrocarbon accumulation system and then quantitatively predict the hydrocarbon accumulation coefficient decreases the influence of human factors in resources evaluation, and makes the resources assessment more objective and closer to the actual geological condition.

Study on fault-controlled hydrocarbon migration and accumulation process and models in Zhu I Depression

Through the analysis of the faults and their internal structure in Zhu I Depression,it is found that the internal structure of the late fault is obviously segmented vertically.It develops unitary structure(simple fault plane)in shallow layers,binary structure(induced fracture zone in hanging wall and sliding fracture zone in footwall)in middle,layers and ternary structure(induced fracture zone in hanging wall and sliding fracture zone in middle,and induced fracture zone in footwall)in deep layers.Because the induced fracture zone is a high porosity and permeability zone,and the sliding fracture zone is a low porosity and ultra-low permeability zone,the late fault in middle layers has the character of"transporting while sealing".The late fault can transport hydrocarbon by its induced fracture zone in the side of the hanging wall and seal hydrocarbon by its sliding fracture zone in the side of the footwall.In deep layers,the late fault has the character of"dual-transportation",induced fracture zones in both sides of hanging wall and footwall can transport hydrocarbon.The early fault that only developed in the deep layers is presumed to be unitary structure,which plays a completely sealing role in the process of hydrocarbon migration and accumulation due to inactivity during the hydrocarbon filling period.Controlled by hydrocarbon source,early/late faults,sand bodies and traps,two reservoir-forming models of"inverted L"and"stereo-spiral"can be proposed in middle layers,while two reservoir-forming models of"cross fault"and"lateral fault sealing"are developed in the deep layers of Zhu I Depression.

Simulation of the Accumulation Process of Biogenic Gas Hydrates in the Shenhu Area of Northern South China Sea

Previous work has largely discussed the relations between sediment structures and accumulation of gas hydrates in the Shenhu area of South China Sea, but has not documented why the gas hydrates occurred at the seafloor topographic highs. Many gas hydrate exploration examples abroad also indicate that the saturation of gas hydrates was higher at seafloor topographic highs. This work aims to understand why gas hydrates accumulated at topographic highs and why their saturation is higher.

Hydrocarbon Accumulation Process in the Marine Strata in Jianghan Plain Area, Middle China

Marine strata in the Jianghan Plain area are widely distributed with a total depth of more than 8,000 m from the Upper Sinian to the Middle Triassic. Six reservoir caprock units, named Z-C2, C2-O, S, D--C, P and T1, can be identified with each epoch. The geology, stratigraphy, drilling, oil testing and other basic data as well as the measured inclusion and strontium isotope data in the study area are used in the analysis of the formation and evolution process of marine petroliferous reservoirs in the Jianghan Plain area. This study aims to provide a scientific basis for the further exploration of hydrocarbons in the Jianghan Plain and reduce the risks by analyzing the key factors for hydrocarbon accumulation in the marine strata. Our findings show that in the Lower Palaeozoic hydrocarbon reservoir, oil/gas migration and accumulation chiefly occurred in the early period of the Early Yanshanian, and the hydrocarbon reservoir was destroyed in the middle-late period of the Early Yanshanian. In the Lower Triassic-Carboniferous hydrocarbon reservoir, oil/gas migration and accumulation chiefly occurred in the Early Yanshanian, and the hydrocarbon reservoir suffered destruction from the Late Yanshanian to the Early Himalayanian. The preservation conditions of the marine strata in the Jianghan Plain area have been improved since the Late Himalayanian. However, because all source beds have missed the oil/gas generation fastigium and lost the capacity to generate secondary hydrocarbon, no reaccumulation of hydrocarbons can be detected in the study area＇s marine strata. No industrially exploitable oil/gas reservoir has been discovered in the marine strata of Jianghan Plain area since exploration began in 1958. This study confirms that petroliferous reservoirs in the marine strata have been completely destroyed, and that poor preservation conditions are the primary factor leading to unsuccessful hydrocarbon exploration. It is safely concluded that hydrocarbon exploration in the marine strata of the study area is quite risky.

Source and accumulation process of Jurassic biodegraded oil in the Eastern Junggar Basin,NW China

Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegraded oil from multiple sources has always been a hard nut to crack.Rising to this challenge,in this study-we carried out a comprehensive investigation of biodegradation impacts,oil-source correlation,and oil charging history to trace the source and reveal the mixing process of biodegraded oil in the Toutunhe Formation(J_(2)t)in the eastern Junggar Basin,NW China.The oil of this area was biodegraded to different extent,consequently,many commonly used biomarker parameters(e.g.Pr/Ph,Pr/n C_(17))became less powerful for oil-source correlation.To address this problem,the resistance of many biomarkers to biodegradation was analyzed,and those of high bio resistance were selected to generate a more reliable oil-source correlation.The results revealed that biodegraded oil was a mixture of oil sourced from Lucaogou Formation(P_(2)l)and Xiaoquangou Formation(T_(2-3)xq).Core sample observation,microscopic fluorescent analysis and fluid inclusion analysis were combined to analyze comprehensively oil charging history.The analysis of accumulation process exhibited that the existing oil in J_(2)t was a mixture originated from the P_(2)l and T_(2-3)xq source rocks in two separate charging stages when it underwent a complicated process of charging,biodegradation,recharging and mixing.

Control of neotectonic movement on hydrocarbon accumulation in the Kuqa Foreland Basin,west China

Neotectonic movement refers to the tectonic movement that has happened since the Cenozoic, which is the latest movement. It has the most important influence on the basins in west China, especially on the hydrocarbon accumulation in the western foreland basins. We determined the time of neotectonic movement in the Kuqa Foreland Basin, which began from the Neogene, and analyzed the patterns of movement, which were continuous and fast subsidence in the vertical direction and intense lateral compression. The structure styles are that the faulting is weakened and the folding is strengthened gradually from north to south. We studied the control of neotectonic movement on the hydrocarbon accumulation process and model in the Kuqa Foreland Basin with basin simulation technique. The largest subsidence rate of the Kuqa Foreland Basin reached 1,200 m/Ma during the neotectonic movement, leading to rapid maturing of source rock within 5 Ma and a large quantity of hydrocarbon being generated and expelled. The thick neotectonic strata can form high quality reservoirs with the proved gas and oil reserves accounting for 5% and 27% of the total reserves, respectively. 86% of the structural traps were formed in the neotectonic movement period. The faults formed during the neotectonic movement serve as important migration pathways and they exist in the region where the hydrocarbon reservoirs are distributed. Abnormally high pressure caused by the intense lateral compression, thick neotectonic strata deposition and rapid hydrocarbon generation provide driving force for hydrocarbon migration. The accumulation elements match each other well over a short period, leading to many large gas fields formed later in the Kuqa Foreland Basin.

Dynamic Systems of Petroleum Accumulation in the Nanpu Depression,Bohai Bay Basin,China

It is significant to distinguish the dynamic systems of petroleum accumulation （DSPA） for the understanding of petroleum accumulation and distribution. According to the formation pressure framework, genetic types of petroleum and characteristics of conduit systems, three dynamic systems of petroleum accumulation were identified in the vertical profile in the Nanpu depression, Bohai Bay basin. The deeper DSPA （including formations Es3 to Es2） is a sealed system with high-overpressure and high-mature self-sourced oil. Most of the crude oil in the system accumulated in the periods of late Oligocene （23.5 Ma） and late Pliocene （2.4 Ma）. The middle DSPA （including formations Es~ to Edl） is an overpressured half-sealed system with mature or lower-mature self-sourced oil. The accumulation of oil in the system also occurred in the late Oligocene （23.5 Ma） and late Pliocene （2.4 Ma）. The shallower DSPA （including formations Ed2 to Q） is a hydrostatic system with lower-mature aliensourced oil from the middle system. Oil within this system accumulated only in the late Pliocene period. The oil in the shallower system migrated vertically along the faults from the formerly accumulated oil in the middle system by lateral migration along the sandbodies, whereas petroleum accumulation in the deeper system was mainly derived from the system itself by lateral migration along the sandbodies and rarely migrated out of the system. In this case, it seems that the deeper system is a more potential exploration prospect in addition to the other two proved favorable systems.

Stress and Strain Accumulation Due to a Long Dip-Slip Fault Movement in an Elastic-Layer over a Viscoelastic Half Space Model of the Lithosphere-Asthenosphere System

Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situated in an elastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving associated boundary value problem with the help of integral transformation and Green’s function method and a suitable numerical methods is used for computation. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.

Dynamic control of a firm’s process innovation with knowledge accumulation in a vertically differentiated monopoly

This paper explores a multiproduct firm’s process innovation of high-and lowquality goods with knowledge accumulation in a vertically differentiated monopoly.We show that:(i)the system admits a saddle-point steady-state equilibrium under firm decision-making and social planner adjustment,respectively;(ii)the firm’s learning rates of knowledge accumulation of process innovation call for more intense efforts in both directions;(iii)there is a substitution between the process innovation for these two kinds of goods;(iv)the social incentive towards both kinds of innovation efforts is always larger than the private incentive characterizing the profit-seeking firm.Our contribution extends the dynamic innovation literature that focuses on singlegood and considers the effects of corresponding knowledge accumulation on process innovation of these two kinds of goods.Further,this theoretical work contributes to the design of efficient innovation effort strategies for firms’process innovation with corresponding knowledge accumulation in a vertically differentiated monopoly market.

Model-based evaluation on the conversion ratio of ammonium to nitrite in a nitritation process for ammonium-rich wastewater treatment

Modeling for nitritation process was discussed and analyzed quantitatively for the factors that influence nitrite accumulation. The results indicated that pH, inorganic carbon source and Hydraulic Retention Time(HRT) as well as biomass concentration are the main factors that influenced the conversion ratio of ammonium to nitrite. A constant high pH can lead to a high nitritation rate and results in high conversion ratio on condition that free ammonia inhibition do not happen. In a CSTR system, without pH control, this conversion ratio can be monitored by pH variation in the reactor. The pH goes down far from the inlet level means a strongly nitrite accumulation. High concentration of alkalinity can promoted the conversion ratio by means of accelerating the nitritation rate through providing sufficient inorganic carbon source(carbon dioxide). When inorganic carbon source was depleted, the nitritation process stopped. HRT adjustment could be an efficient way to make the nitritation system run more flexible, which to some extent can meet the requirements of the fluctuant of inlet parameters such as ammonium concentration, pH, and temperature and so on. Biomass concentration is the key point, especially for a CSTR system in steady state, which was normally circumscribed by the characteristics of bacteria and may also affected by aeration mode and can be increased by prolonging the HRT on the condition of no nitrate accumulation when no recirculation available. The higher the biomass concentration is, the better the nitrite accumulation can be obtained.

An Improved Analytic Hierarchy Process and Application in Grain Production

Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process （AHP） accumulation factor, namely Solving Weight by AHP＇s Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable

Effects of Aeration on Nitrification Process in a Polluted Urban River

[Objective] The study aimed to discuss the effects of aeration on nitrification process in a polluted urban river, [Metbod] Through indoor simulation experiments, the effects of different aeration conditions （aerating water named Ew, aerating sediment named Es ） on nitrification process in a polluted urban river were studied.[ Result]The nitrification of the control group named Ec proceeded slowly, while two kinds of aeration promo- ted the process of nitrification, that is, the peak values of nitrate nitrogen of Ew and Es group were respectively 5.15 and 3.83 times that of Ec group. During aeration, NO2 --N accumulation in the overlying water of Ew and Es group lasted for 10 and 14 days separately, and the maximum concentrations reached 11.41 and 7.41 mg/L respectively. Nitrification process was not consistent during the two aeration conditions, that is, the rate of nitrite oxidation in Ew group was faster than that in Es group. Denitrification process was significant after aeration, and the concentration of nitrate nitrogen in Ew and Es group was 1.26 and 2.82 mg/L respectively at the end of the experiment. [ Conclusion]The research could provide scientific references for the restoration of polluted urban rivers.

A Double Shot Noise Process and Its Application in Insurance

The authors consider a compound Cox model of insurance risk with the additional economic assumption of a positive interest rate. As the authors note a duality result relating a compound Cox model of insurance risk with a positive interest rate and a double shot noise process, the authors analyze a double shot noise process systematically for its theoretical distributional properties, based on the piecewise deterministic Markov process theory, and the martingale methodology. The authors also obtain the moments of aggregate accumulated/discounted claims where the claim arrival process follows a Cox process with shot noise intensity. Removing the parameters in a double shot noise process gradually, the authors show that it becomes a compound Cox process with shot noise intensity, a single shot noise process and a compound Poisson process. Numerical comparisons are shown between the moments （i.e. means and variances） of a compound Poisson model and their counterparts of a compound Cox model with/without considering a positive interest rate. For that purpose, the authors assume that claim sizes and primary event sizes follow an exponential distribution, respectively.

Rainfall Estimation using Image Processing and Regression Model on DWR Rainfall Product for Delhi-NCR Region

Observed rainfall is a very essential parameter for the analysis of rainfall,day to day weather forecast and its validation.The observed rainfall data is only available from five observatories of IMD;while no rainfall data is available at various important locations in and around Delhi-NCR.However,the 24-hour rainfall data observed by Doppler Weather Radar(DWR)for entire Delhi and surrounding region(up to 150 km)is readily available in a pictorial form.In this paper,efforts have been made to derive/estimate the rainfall at desired locations using DWR hydrological products.Firstly,the rainfall at desired locations has been estimated from the precipitation accumulation product(PAC)of the DWR using image processing in Python language.After this,a linear regression model using the least square method has been developed in R language.Estimated and observed rainfall data of year 2018(July,August and September)was used to train the model.After this,the model was tested on rainfall data of year 2019(July,August and September)and validated.With the use of linear regression model,the error in mean rainfall estimation reduced by 46.58% and the error in max rainfall estimation reduced by 84.53% for the year 2019.The error in mean rainfall estimation reduced by 81.36% and the error in max rainfall estimation reduced by 33.81%for the year 2018.Thus,the rainfall can be estimated with a fair degree of accuracy at desired locations within the range of the Doppler Weather Radar using the radar rainfall products and the developed linear regression model.

Grey GRM(1, 1) Model Based on Reciprocal Accumulated Generating and Its Application

Aiming the problem of low accuracy during establishing grey model in which monotonically decreasing sequence data and traditional modeling methods are used, this paper applied the reciprocal accumulated generating and the approach optimizing grey derivative which is based on three points to deduce the calculation formulas for model parameters, established grey GRM(1, 1) model based on reciprocal accumulated generating. It provides a new method for the grey modeling. The example validates the practicability and reliability of the proposed model.

Measuring potential food productivity for different areas in Songnen Plain based on analytic hierarchy process

The improved analytic hierachy process method was utilized in this paper,and a variety of factors influencing the food production were classified into several interrelated orderly objectives layers;based on the works above,this paper made an scientific assessment on the influencing factors of food production and production potential of the various regions in the Songnen Plain.The weights and composite indices were calculated with the method of solving weight by AHP's accumulation factor sequence evaluating data,and were processed by single-level sorting and general sorting.The result showed that,the region of Changchun had the biggest potential for improving food production,but smallest for Heihe region.The key reason for the food production discrepancy of a variety of regions in Songnen Plain is the differences in scale of production and climatic conditions,the weight coefficients of which are 0.3654 and 0.2742;however,the weight coefficients of agricultural science and technology investment is very low just 0.1703,which should be increasted in the future.

Geochemical constraints on mixed source and hydrocarbon filling process in theYingjisu Sag,Tarim Basin,Xinjiang

The Yingjisu Sag was petroliferous for normal oil, condensate oil, reservoir bitumen and natural gases. Geochemical studies showed that natural gases in the Yingjisu Sag were a gas mixture consisting mainly of Cambrian pyrolysis gas, Jurassic condensate oil in well Yingnan 2 and normal oil in well Tadong 2, reflecting the characteristics of marine-phase gases and oils, while crude oils in well Longkou 1 demonstrated the characteristics of both marine and terrestrial oils, which were derived from lower algae and higher plants. Jurassic oils from wells Longkou 1 and Huayingcan 1 and Cambrian crude oils from well Tadong 2 were derived mainly from Cambrian-Lower Ordovician source rocks. Jurassic and Silurian reservoir bitumens from well Yingnan 2 were biodegradated, suggesting they are of marine and terrestrial origins. The bitumens have similar geochemical characteristics, which are correlated well with Ordovician crude oils from well Tadong 2 and Jurassic condensate oil from well Yingnan 2. Based on the characteristics of tectonic evolution in this area and the analysis of hydrocarbon accumulation, the constraints on the mixed source and hydrocarbon filling process in the Yingjisu Sag were brought forward.

盐构造活动对油气成藏的控制作用:以下刚果盆地为例

盐构造对油气藏成藏具有重要的控制作用,很多富油气盆地都发育丰富的盐构造。本论文以南大西洋东海岸下刚果盆地为研究对象,从含油气盆地分析的角度,以构造地质学、沉积学和成藏动力学系统理论为指导,旨在明确盐岩构造变形特征及演化过程的基础上,分析盐岩构造变形对盐相关油气成藏的控制作用。基于二维和三维地震资料解释成果,识别出下刚果盆地发育盐滚、盐底辟、盐蓬/盐盖、厚层盐岩4种主要盐岩构造样式,明确了各类盐构造的变形特征及其上覆地层构造特征。最后,在分析盐构造变形对源、储、圈闭等静态成藏要素,以及圈闭演化过程、油气运移、保存等动态成藏过程影响的基础上,建立下刚果盆地油气动态成藏模式,以期指导该盆地下一步油气勘探。

相干累加与AR滤波相结合的舰船轴频电场信号处理方法

针对采用电场传感器阵列测量舰船电场的应用场景,为提升目标轴频电场的信噪比,提出一种相干累加结合自回归(autoregressive,AR)模型滤波的方法对阵列电场信号进行处理。对测量得到的阵列电场信号进行时延补偿后累加,同时对环境电场信号进行AR建模,并利用AR模型参数构造滤波器,以对累加后的信号实施滤波处理。为验证所提方法在低信噪比条件下的有效性,对实测阵列式电场信号进行处理,结果表明,所提方法能够在信噪比为-25.39 dB的条件下有效压制噪声频谱,保留轴频线谱,处理后信噪比提高约21.92 dB。

川西地区雷口坡组储层流体包裹体特征与成藏期次

以地震、钻井、岩心和包裹体薄片等资料为基础,结合区域构造演化和烃源岩生排烃过程,通过对川西地区中三叠统雷口坡组储层流体包裹体岩相学分析、均一温度及盐度测定、埋藏—热演化史模拟和气藏演化过程分析等,明确雷口坡组油气充注时间和期次,分析不同类型气藏的成藏过程。结果表明:川西探区雷口坡组包裹体成群/成带发育于孔洞矿物充填期后,丰度较低(GOI为1%±),均为灰色—深灰色含烃盐水包裹体;均一温度在90℃~200℃,温度峰值在120℃~150℃;盐度分布在0~24%,具体可细分为0~4%、6%~18%和20%~24%共3个区间。川西探区雷口坡组天然气主成藏期有3期,分别为晚三叠世末期、早侏罗世晚期至晚侏罗世早期和新近纪—第四纪。油气成藏过程为晚三叠世,上二叠统龙潭组和中三叠统雷口坡组烃源岩进入生油高峰,生成原油沿印支运动形成的断裂进入雷四段储层形成古油藏;早-中侏罗世,两套烃源岩进入生气高峰,叠加古油藏裂解生气形成气藏,斜坡区马鞍塘组烃源岩进入生油高峰,沿不整合面侧向运移至雷四段储层形成古油藏;新近纪以来,油气藏最终调整定型形成现今形态。