Hasil untuk "Petroleum refining. Petroleum products"

NIU HUAWEI, YANG PENGCHENG, LIU CHUANG et al.

A gasfield with reserves exceeding 100 billion cubic meters has been discovered in the Central Canyon on the southern slope of the Lingshui Sag in Qiongdongnan Basin. However, the northern slope shows poor oil and gas enrichment, with gas detected but no fields found. One of the key reasons is the absence of large-scale high-quality reservoirs encountered during drilling. To clarify the sedimentary evolution model and distribution patterns of high-quality sand bodies on the northern slope of the Lingshui Sag, this study integrated drilling, logging, mud logging, testing, and seismic data, using techniques such as thin section observation, grain size analysis, and physical property testing. Core facies, logging facies, and seismic facies analyses were carried out for the key strata to establish the sedimentary evolution model of Meishan Formation. Combined with reservoir microscopic characteristics and fault-sand matching, the oil-gas geological significance was clarified. The results showed that during the Meishan Formation period, sediment sources were provided by Hainan Island, and a shelf delta-submarine fan sedimentary system was developed. In the study area, the microfacies sand bodies of channels and channel-lobe complexes were relatively coarse and thick, with box-shaped or bell-shaped logging curves, and stratification and bioturbation were observed in the cores. Seismic data showed U-shaped or V-shaped low-frequency continuous parallel reflections, which served as the main exploration targets in the study area. The development of submarine fans and the differentiation of their internal sand bodies were mainly controlled by fluctuations in relative sea level, paleogeomorphic features, and the intensity of sediment supply. During the second member of the Meishan Formation (hereinafter referred to as Meishan 2) period, the relative sea level dropped, the sediment supply was abundant, and the relative accommodation space was relatively small, with <italic>A</italic>/<italic>S</italic> ≤ 1 (<italic>A</italic> representing relative accommodation space and <italic>S</italic> representing sediment supply). Sediments were transported over long distances to the continental slope, forming multiple phases of submarine fan progradation. Laterally, the development of submarine fans and the differences within their internal sand bodies were controlled by paleogeomorphology and distance from the sediment source, mainly developing in the proximal slope break zones and fault-controlled slope break zones formed by synsedimentary faults. The Meishan 2 reservoirs in the study area had porosity ranging from 8.40% to 26.24%, and permeability ranging from 0.05×10^-3 µm² to 26.49×10^-3 µm², mainly characterized by medium porosity and ultra-low to low permeability. High-quality reservoirs were controlled by late-stage reworking. Contour currents could wash, transport, and redeposit gravity flow sediments formed earlier, significantly improving reservoir physical properties. Under the general background of sand deficiency in the study area, the coupling between faults and sand bodies constrained the degree of oil and gas enrichment. Drilling results showed that oil and gas were highly active near the No.2 fault zone. The sand body enrichment zone of the No.2 fault zone was an important oil and gas target for future exploration.

Li Wanzhong, Zhang Zhenyu, Xu Jianning et al.

To address the underperformance of jet pump deliquification in high water cut tight gas reservoirs of Qingshimao field， optimizing the jet pump deliquification technology of high water-cut tight gas reservoirs is imperative. In the paper， based on the overall production characteristics and well condition parameters of gas wells in the Qingshimao field， considering the technical characteristics of jet pump deliquification technology under the action of water and natural gas， combined with numerical analysis and test， the internal flow field of jet pump was analyzed. Then， taking Well Li⁃x as an example， the characteristics of two jet pump deliquification technologies were analyzed， and the jet pump deliquification technology for high water-cut tight gas reservoirs was optimized. The study results show that the liquid-gas alternating jet pump deliquification technology adopts short-cycle alternating operations. This approach incorporates the advantage of hydraulic jet pump deliquification technology such as strong liquid-carrying capacity， enabling rapid gas well restoration. Meanwhile， it combines the advantage of pneumatic jet pump deliquification technology such as unaffected by liquid column backpressure in the gas well production， allowing the restored well to transition directly to flow production. The liquid-gas alternating jet pump deliquification technology increases gas production by 20% compared to the hydraulic （water） jet pump deliquification technology， and increases liquid production by 116% and reduces composite cost by 32% compared to the pneumatic （natural gas） jet pump deliquification technology. The study results provide experimental basis and theoretical reference for the optimization of jet pump deliquification technology for high water-cut tight gas reservoirs.

WU Xi

The Qinshui Basin is the main production base of high-rank coalbed methane in China. High-rank coal reservoirs in this region exhibit diverse conditions for coal formation and reservoir development, complex geological structures, low permeability, pronounced reservoir heterogeneity, and significant challenges in reservoir stimulation, which led to early issues such as a low effective resource utilization rate, low gas production per well, and low development profits. By analyzing the characteristics of high-rank coal reservoirs and the development patterns of coalbed methane, this study identifies three key constraints to the efficient development of high-rank coalbed methane: (1) poor precision in selecting areas for efficient development; (2) limited adaptability of development technologies; (3) a mismatch between stimulation processes and coal reservoirs. Investigations into microstructures, coal body structures, in-situ stresses, and fractures—combined with an evaluation of various geological factors’ impact on production—enabled a multidimensional division of development units to identify the geological features of each unit. Consequently, a “five-element” evaluation index system for production potential in efficient development areas was established, and an optimization method for selecting efficient development areas for high-rank coalbed methane was formulated. Analysis suggests that due to the low permeability and strong heterogeneity of high-rank coal, horizontal wells can connect more coal seam fractures, thereby expanding the drainage and pressure-relief areas and reducing the flow resistance of gas and water. This possesses advantages such as high per-well gas production and improved economic benefits. For different geological zones and development stages, in accordance with the principle of “maximizing controlled reserves, maximizing gas production rate, and optimizing economic benefits”, an optimized horizontal well layout technology for high-rank coalbed methane was developed. On this basis, with the objective of “initiating a fracture network, creating new fractures, and controlling reserves”, key technologies were devised—primarily including energy-focused directional perforation, stepwise hydraulic fracturing for incremental production enhancement, a combined application of fine-powder sand, and synchronous well-group interference. At the same time, the process technologies of bridge-plug-and-perforation using active water as the main body and well-group synchronous interference operations were refined, leading to the establishment of a linear fracture network system conducive to gas production, achieving efficient hydraulic fracturing. The application of these research outcomes in the Qinshui Basin has enabled the efficient development of high-rank coal, with daily gas production per horizontal well doubling, the ultimate recoverable reserve per well increasing by 50%, and the productivity attainment rate of newly-built blocks surpassing 90%. When extended to other high-rank coalbed methane blocks in China, these advantages provide technical support and a demonstrative model for strengthening the coalbed methane industry.

Huiying TANG, Shangui LUO, Haipeng LIANG et al.

Based on the displacement discontinuity method and the discrete fracture unified pipe network model, a sequential iterative numerical method was used to build a fracturing-production integrated numerical model of shale gas well considering the two-phase flow of gas and water. The model accounts for the influence of natural fractures and matrix properties on the fracturing process and directly applies post-fracturing formation pressure and water saturation distribution to subsequent well shut-in and production simulation, allowing for a more accurate fracturing-production integrated simulation. The results show that the reservoir physical properties have great impacts on fracture propagation, and the reasonable prediction of formation pressure and reservoir fluid distribution after the fracturing is critical to accurately predict the gas and fluid production of the shale gas wells. Compared with the conventional method, the proposed model can more accurately simulate the water and gas production by considering the impact of fracturing on both matrix pressure and water saturation. The established model is applied to the integrated fracturing-production simulation of practical horizontal shale gas wells. The simulation results are in good agreement with the practical production data, thus verifying the accuracy of the model.

Zhong Jian, Ma Xiao, Hou Xueli et al.

An auxiliary measurement system of nuclear magnetic resonance(NMR)logging tool based on universal acquisition platform was designed to enable the new generation of NMR logging tool to efficiently and accurately acquire information about auxiliary measurement parameters.Based on the universal acquisition platform technology,a detailed analysis was conducted on the necessary parameters and properties in auxiliary measurement of NMR logging tool,and an auxiliary measurement system of NMR logging tool was proposed.The design and realization of the hardware functions(e.g.signal conditioning,multichannel switching and digital-analog conversion)of the auxiliary measurement system,as well as the time sequence of sending auxiliary measurement parameter selection channel commands and reading auxiliary measurement parameter acquisition data,were investigated.The single board test results show that the selection of auxiliary measurement parameter channels and the uploading of acquired data are feasible.The joint debugging test results show that the designed auxiliary measurement system can accurately obtain the information about auxiliary measurement parameters of NMR logging tool,and reflect the actual working status of the tool.The research results provide a technical basis for the design,research and application of auxiliary measurement systems of eccentric,while drilling and through-bit NMR logging tools.

Ankita Kukshal, Ravi Sharma, Hirak Jyoti Kalita et al.

Abstract One of the main challenges for healthy hydrocarbon yields from the production wells is the sand production, and its control assumes significant importance for successful production operations. The prime objective remains to control the sand production without compromising on the fluid flow rates. Sand production is conventionally associated with diverse heterogeneous formations, especially poorly consolidated formations. Scrutinizing fluid flow rates at different orientations of perforations is a valuable analysis in controlling the sand production. This study was conducted to examine the case of sand production in a few development wells from Malleshwaram field of the Krishna Godavari (KG) basin in south India and provide alternatives to arrest this sand production. The influence of oriented perforations on fluid flow rates to minimize sanding tendencies was examined. Sand grain diameter was estimated using the distribution plots of the grain sizes obtained from the photomicrographs, and the average value of the grain size was estimated around 100 μm. The fluid flow model was simulated for actual scenario in the hydrocarbon bearing Nandigama formation using finite element modeling (FEM). Sanding tendencies in these formations were studied at varying depletion rates. Critical draw down pressure (CDDP), which is a function of both critical bottom hole pressure and reservoir pore pressure, for well 1 and well 2 is estimated as 4650 Psi and 3400 Psi, respectively, at 0% depletion. CDDP was used to estimate the onset of sanding, and the flow rate for horizontal perforation was calculated as 0.024548 $${\mathrm{m}}^{3}$$ m 3 /sec. Strength parameters, namely the unconfined compressive strength (UCS) and cohesion, were also investigated in all the wells to decipher the formation strength and a possible linkage to sanding. These results present a completely fresh analysis of the sanding potential and the related parameters responsible for it in these formations. Fluid flow rates for the producing reservoir are studied at different set of oriented and sized perforations. It was observed that a hiked flow rate in horizontal perforations maintains the production in a safe and no-sanding zone. This study provides vital information and a workflow for similar heterogeneous complex formations for designing the well completions, augmenting economic production and reinforcing future reservoir management.

ZHANG Yixiao, LI Xiaobo, SHANG Genhua et al.

The connected media of fault-karst reservoir are fractures, caves and pores, the decrease of pressure will lead to the decrease of permeability and conductivity, which will have an irreversible impact on oil well production. According to the stress-sensitive characteristics of fault-karst reservoir, 72 groups of physical simulation experiments on conductivity are designed and carried out to analyze the stress-sensitive characteristics of different connected media and influencing factors. Based on the results of physical simulation experiment and the theory of porous flow, a numerical inversion model of flow in fractured solution reservoir is established, and the stress sensitivity effect caused by reservoir pressure drop on oil well production is studied. The results show that the pressure drop has great influence on the conductivity, productivity and recovery ability of different connected media. The pressure inflection points of fracture type, karst cave type and pore type are 5.3 %, 20.4 % and 35.1 %, respectively, and the conductivity loss of the first two are 99.7 % and 45.0 %. The conductivity loss of pore type decreases linearly in the test range. The research on the characteristics of pressure drop inflection point provides the basis for reasonable production control and the determination of energy replenishment time, and has important guiding significance for stable production of oil wells.

A FALAVAND-JOZAEI, E HAJIDAVALLOO, Y SHEKARI et al.

The present study aims at investigating the effect of temperature variation due to heat transfer between the formation and drilling fluids considering influx from the reservoir in the underbalanced drilling condition. Gas-liquid-solid three-phase flow model considering transient thermal interaction with the formation was applied to simulate wellbore fluid to calculate the wellbore temperature and pressure and analyze the influence of different parameters on fluid pressure and temperature distribution in annulus. The results show that the non-isothermal three-phase flow model with thermal consideration gives more accurate prediction of bottom-hole pressure (BHP) compared to other models considering geothermal temperature. Viscous dissipation, the heat produced by friction between the rotating drilling-string and well wall and drill bit drilling, and influx of oil and gas from reservoir have significant impact on the distribution of fluid temperature in the wellbore, which in turn affects the BHP. Bottom-hole fluid temperature decreases with increasing liquid flow rate, circulation time, and specific heat of liquid and gas but it increases with increasing in gas flow rate. It was found that BHP is strongly depended on the gas and liquid flow rates but it has weak dependence on the circulation time and specific heat of liquid and gas. BHP increase with increasing liquid flow rate and decreases with increasing gas flow rate.

WANG Rui

In general, fracturing well pattern is used for the development of low-permeability reservoir. This development process relates to the oil-water two phase flow, while the current researches on fracturing well productivity consider more about single phase flow. Based on the consideration of the reservoir anisotropy, threshold pressure gradient and oil-water two phase flow, a prediction method of fracturing well productivity is proposed by numerical method and sweep theory. And then, a contrast between the calculated results of the proposed method and field data is performed to verify the accuracy of the proposed model. The results show that when the water cut is constant, the increase of fracture conductivity results in the increase of the oil production. However,as the conductivity increases, the increase rate of the oil production decreases. The increase of the fracture conductivity also results in the increase of the cumulative oil production. When the conductivity is greater than 0.4 μm2·m, the cumulative oil production increases slowly. When the length of the fracture increases, the seepage resistance near the bottom decreases, so that the oil production increases. The increase of the permeability ratio indicates the planar heterogeneity becoming stronger, so that the productivity of the fractured well reduces showing a poorer water flooding effect. This study provides a theoretical basis for the optimization of the fracturing of the development well pattern by water flooding.

CHEN Ke, ZHANG Xudong, HE Wei et al.

The geological conditions of marine fluvial sedimentary reservoir are very complex.In the process of water flooding development,the remaining oil distribution is dispersed and it is difficult to develop due to different water absorption in the same permeability reservoir.In order to guide the exploration direction of remaining oil in the later stage of each reservoir,the pore throat distribution characteristics and micro percolation characteristics of different permeability reservoirs are studied based on the micro pore throat scale by the mercury injection experiment and micro water drive visualization experiment.The results show that there is a good logarithmic correlation between the average pore throat radius and permeability,and the correlation coefficient is 0.963 5.With the increase of the reservoir permeability,the mean pore throat radius increases gradually,whereas the micro fingering phenomenon of water drive is reduced,and the water flooding process is gradually changing to finger-network-uniform displacement.Both the sweep efficiency and recovery efficiency of each model show an increasing tendency,and the proportion of continuous remaining oil is gradually decreasing.When the permeability increases to 2 228.7×10^-3μm²,both the sweep efficiency and recovery efficiency reach their maximum value,the for is 82.97%,the latter is 66.1%,and the proportion of continuous remaining oil reaches the minimum value of 45.82%.For the reservoirs with permeability of（73.1～1 005.2）×10^-3μm²,the main direction of potential tapping in the later period should be to increase the viscosity of displacement fluid and increase sweep.For reservoirs with permeability of（1 005.2～3 509.6）×10^-3μm²,it turns to be improving oil displacement efficiency.For reservoirs with permeability of（3 509.6～4 040.6）×10^-3μm²,it is appropriate to increase water injection pressure or block large water breakthrough channels to change the direction of injected water,so as to improve the conformance as the main direction of the potential tapping.

E. B. Krivtsov, A. Goncharov

E. Chernysheva, I. Piskunov, V. Kapustin

WANG Zhe

In order to solve the problems such as coal blockage and low gas production of coalbed methane wells in the Southern Yanchuan block, an application test of controlled shock wave plugging removal and permeability improvement technology is carried out. Therefore, four typical wells are selected to analyze the geological and engineering parameters in the construction process, as well as comparative analysis of the gas and water production before and after the implementation. The results show that the application of controllable shock wave plugging removal and permeability improvement technology in coalbed methane wells can improve liquid fluidity, promote gas desorption and diffusion, and remove plugging in coal reservoirs. The well selection criteria of this technology are low coalbed fracture pressure, good fracturing effect, including dirt band, high gas-bearing capacity of coalbed, relatively high formation pressure coefficient, etc. This technology has the effect of creating fractures and removing plugs, which can improve the fluidity of formation fluids and remove formation pollution. It has a good implementation effect and application prospect in the near-well zone of south Yanchuan coalbed methane wells to plugging removal and increase gas production, and is expected to be a new stimulation technology for low yield and efficiency wells.

Xiaoyi Mu

The availability of low-cost energy from fossil fuels - in particular oil - has been the driving force behind postwar global economic growth, such that the petroleum industry has some of the world's largest companies. This book examines the economics of the oil and gas industry, from exploration, development and production, to transportation, refining and marketing. At each stage of the value chain, the key economic costs and considerations are presented in order to provide the reader with a comprehensive understanding of the workings of the industry. The book examines some of the unique economic challenges the industry faces, including negotiating international contracts with host countries (to gain access to hydrocarbons), managing the risks of recovery, implementing cross-border pipelines, dealing with huge variations in the taxation of refined products, and reacting to the effect of price control and subsidization in the OPEC nations which can create massive volatility in pricing. The search for low-carbon fuels, the impact of shale gas, the prospect of finite reserves, and the global political realities of the competing demands of oil-importing and oil-exporting countries are shown to make the sector high risk, but the economic rewards can be huge.

Haihua ZHU, Tingshan ZHANG, Dakang ZHONG et al.

The pore structure and its influence on physical properties and oil saturation of the Triassic Chang 7 sandstones, Ordos Basin were discussed using thin sections, physical properties, oil saturation and mercury intrusion data. The results show that the tight sandstone has a binary pore structure: when the pore throat radius is larger than the peak radius, the pore radius is significantly larger than throat size, the pore structure is similar to the bead-string model with no fractal feature, and the pore throat volume is determined by the pore volume. When the pore throat radius is smaller than the peak radius, the pore structure is close to the capillary model and shows fractal features, the pore size is close to the throat size, and the pore throat volume is determined by the throat radius. The development of pore throats larger than the peak radius provides most of the oil storage space and is the major controlling factor for the porosity and permeability variation of tight sandstone. The pore throat smaller than the peak radius (including throats with no mercury invaded) contributes major reservoir space, it shows limited variation and has little effect on the change of physical properties which is lack of correlation with oil saturation. The pore throat larger than the peak radius is mainly composed of secondary and intergranular pores. Therefore genesis and main controlling factors of large pores such as intergranular and dissolved pores should be emphasized when predicting the tight sandstones quality. Key words: tight sandstone, pore structure, reservoir, fractal, Triassic Yanchang Formation, Ordos Basin

Norshela Mohd Noh, A. Bahar, Z. Zainuddin

Recently, oil refining industry is facing with lower profit margin due to uncertainty. This causes oil refinery to include stochastic optimization in making a decision to maximize the profit. In the past, deterministic linear programming approach is widely used in oil refinery optimization problems. However, due to volatility and unpredictability of oil prices in the past ten years, deterministic model might not be able to predict the reality of the situation as it does not take into account the uncertainties thus, leads to non-optimal solution. Therefore, this study will develop two-stage stochastic linear programming for the midterm production planning of oil refinery to handle oil price volatility. Geometric Brownian motion (GBM) is used to describe uncertainties in crude oil price, petroleum product prices, and demand for petroleum products. This model generates the future realization of the price and demands with scenario tree based on the statistical specification of GBM using method of moment as input to the stochastic programming. The model developed in this paper was tested for Malaysia oil refinery data. The result of stochastic approach indicates that the model gives better prediction of profit margin.

E. Remišová, M. Holý

In recent years, there has been a further development of refining technology, which make it possible to better use of crude oil, which also has a major impact on the quality of bitumen. Most European refineries, of course, are processing, for reasons of the resale of petroleum products, especially petroleums suitable for the recovery of light and middle fractions. Therefore, light petroleums are required, with low yields of heavy fractions, which are highly economically and in dispositions efficient for processors on the petroleum market. Emphasis is placed on the sulfur content, the paraffin content is no longer the most important aspect. Less important from the perspective of the refinery is the content and the ratio of asphaltenes and maltenes. There is no doubt that we will have to change our view on petroleum products. Their availability will continue to decline, their price, on the other hand, is likely to grow in relation to falling supplies of resources. Therefore, the view of the bitumen must be changed. The most common way of production of PG bitumen is vacuum distillation, which is carried out in such a way that the vacuum distillation residue satisfies it ́s properties bitumen requirements for the relevant penetration.

Jingnan ZHANG, Qinfeng DI, Shuai HUA et al.

A visualization experimental method of foam flooding was developed by combining nuclear magnetic resonance (NMR) and traditional core flooding method. On this basis, a new method to evaluate the dynamic stability of foam in the core during displacement process was established. Using this method, the displacement characteristics and dynamic stability of foam of S-2 (the main component is sodium lauryl sulfate) and S-NP-2 (the main components are sodium lauryl sulfate and silica nanoparticles) in two different displacement modes, i.e. direct foam flooding and foam flooding after water flooding, were studied. The results show that the NMR images and the T2 (transverse relaxation time) spectrum reflected the displacement characteristics. The flooding efficiency of S-2 and S-NP-2 after water flooding was increased by 18.05% and 25.68% and reached 63.72% and 67.50% respectively at last, higher than direct foam flooding. The same foam system had better stability in foam flooding after water flooding than in direct foam flooding, and foam S-NP-2 is more stable than foam S-2 under the same displacement mode. Key words: foam flooding, flooding experiment, flooding efficiency, nuclear magnetic resonance (NMR), foam stability, evaluation method

Refaat A. El-Adly, Gamal M. Turky

Grease lubrication is a complex mixture of science and engineering, requiring an interdisciplinary approach, and is applied to the majority of bearings worldwide. Grease can be more than a lubricant; it is often expected to perform as a seal, corrosion inhibitor in electrical joints, electrical insulator and electrical connection improver. This work is concerned, therefore, with the comparative study between prepared electrical grease and the imported one. Physicochemical and electrical properties for the prepared grease and the imported one were evaluated. The results of dropping point, penetration, dynamic viscosity, corrosion inhibition, evaporation loss, total acid number and oil separation for the prepared grease under investigation are mostly the same compared with the imported grease. In addition, the results interpreted in terms of the physical and chemical properties of both greases revealed that no remarkable differences. In this respect, calorimetric study shows that the prepared grease, like the imported one, is thermally stable up to about 200 °C then decomposition and degradation started slightly faster and higher than that of the imported one. The electrical and dielectric parameters are very close at and around room temperature then the increase of charge carriers' mobility at higher temperatures explains the deviation from stability in case of the prepared grease. One can conclude that the prepared electrical grease could replace efficiently the imported electrical grease especially in isothermal application at and around room temperature. Keywords: Electrical greases, Electrical joints, Permittivity, Dielectric loss, Thermal stability

C. S. Hsu, P. Robinson