Hasil untuk "Petroleum refining. Petroleum products"

Daukaev A.A., Abubakarova E.A.

The article is devoted to the study of the problem of deep formation replenishment of petroleum reserves using the example of long-term developed fields of two petroleum provinces of Russia in the modern concepts of oil and gas formation and accumulation. Fundamental, published sources and other factual data on the fields of the North Caucasus and Volga-Ural regions of the Russian Federation were used. As a result of the comparative analysis, several analogies in the geological structure and nature of oil and gas potential of long-term developed fields of different regions were revealed.

Raafat Aborafia, Amir Hossein Saeedi Dehaghani

This study investigates the phase behavior of methane, ethane, and their binary mixture in both bulk and 5 nm slit-like pores with silica, anhydrite, calcite, dolomite, and montmorillonite walls using grand canonical Monte Carlo simulation (GCMC). The results show that vapor densities increase and, liquid densities decrease with the reduction of the pore width for both pure components and binary mixtures. The critical pressure and temperature decrease significantly in confined systems compared to bulk systems, with the rate of decrease varying depending on the type of surface. The response of critical density to surface type is distinct, and the critical density can be higher or lower than that in bulk systems. Furthermore, the dew point pressure of the confined binary mixture between two surfaces of silica, anhydrite, calcite, dolomite, and montmorillonite is higher than its value in bulk systems, while the bubble point pressure in confined systems can be lower, equal, or more than its value in bulk systems, depending on the pore surface and temperature.

Ivan Kurnia, Muhammad Fatchurrozi, Riyaz Ghulam Anwary et al.

A review of coreflood experiments for chemically enhanced oil recovery (EOR) is presented in this paper, particularly surfactant-polymer (SP) and alkali-surfactant-polymer (ASP) processes. The objective of this review is to gain a general outlook and insight from coreflood experiments injecting SP or ASP slug as tertiary recovery. The discussion is separated into sections based on relevant core and fluid properties as well as surfactant selection and SP/ASP slug design and their impact on incremental recovery. Most studies in this review have been published within the last twenty years but few older coreflood works have been included for benchmarking. Parameters in each reviewed study have been summarized in tables to help readers gain detailed observation. Lessons learned from these past experiments should help other chemical EOR practitioners or students of the field in benchmarking or improving the outcomes of their future SP/ASP experiments.

Jun Jing, Wenyong Ye, Cong Cao et al.

The irregular wellbore trajectory caused by the wellbore deviation and fluctuation makes a significant effect on the torque and drag in extending and direction drilling, especially for wellbore trajectory with obvious deviation in the drilling direction. As a consequence, a new quasi-three-dimensional wellbore tortuosity evaluation method is developed. The new method incorporates the effect of fluctuation frequency and amplitude of oscillating wellbore trajectory; a weight coefficient index that quantifies the effect of tortuosity of one segment trajectory to the entire trajectory; a ‘Peak-Valley’ principle that can decompose the irregular wellbore trajectory in various scale lengths. The studies show that the deflection angle between the segments of tortuous wellbore increases the torque and drag by strengthening the contact behaviors between the drillstring and borehole. Therefore, the deflection angle is introduced to quantify the effect of deviation in the drilling direction on wellbore tortuosity. The evaluation results of two field cases demonstrate the new method which is adapted to the wellbore trajectory fluctuating with various characteristics and can reflect the actual state of wellbore tortuosity with severe oscillation more effectively and accurately.

Jia Zongwen, Fan Baitao, Liu Zhaonian et al.

In view of the shortcomings existed in traditional wellbore preparation,a casing hydraulic lifting tool was developed,and a casing recovery process was designed.By means of theoretical analysis,the lifting capacity of the tool was calculated,the strength of hydraulic booster cylinder,anchoring mechanism and piston rod under working conditions were checked; the stress effect of anchoring mechanism on the casing inwall was studied; the theoretical and technological research on different application scenarios of the tool were carried out; and simultaneously,field application was conducted for the tool in the Bohai Oilfield.The research and field application results show that the casing hydraulic lifting tool has lifting capacity of more than 3 000 kN,each component of the tool can withstand the stress load produced by lifting operation,and does not cause damage to the inner wall of the casing; the tool is applicable to various application scenarios such as inner casing recovery,riser recovery and multilayer casing recovery.At the time of recovering inner casing,the tool can recover the cemented casing with the length of 2.7～13.0 m(taking the commonly used ø244.48 mm casing for example); at the time of recovering multilayer casing below the mud line,the tool can recover different types of conductor/casing assembly with the length of more than 20.0 m.The combined drilling tool of cutter + casing trip spear + casing hydraulic lifting tool can save 2 trips of tripping,saving 71.3% construction period than the conventional milling recovery process.The conclusions provide technical support for the large-scale application of this tool offshore.

TANG Botao, ZENG Ji, CHEN Weihua et al.

In order to solve the problems that the natural cracks of the dense sandstone reservoir in Sichuan region is undeveloped with low hole, low permeability and strong spatial heterogeneity, the transformation idea of “segment clusters created + sand + high strength long slot” is established by the indoor model experiments. On this basis, a calculation model of stress field around the wells based on the effective stress theory is established. Meanwhile, the above model is combined with the flow-stress coupling fracture extension model for horizontal wells to clarify the influence mechanism of cluster spacing on the crack competition expansion and interseam seepage interference. Therefore, the non-uniform arrangement method of cracks in the sand body of river channel considering stress interference and seepage shadow is formed. It is concluded that the optimal spacing of multiple clusters in the horizontal well section of dense sandstone in Qiulin is seven to twelve meters, which can make the opening rate of the injection cluster up to 92.3 %. This method effectively improves the effect of the transformation of the tight gas reservoirs.

WANG Junheng, WANG Jian, ZHOU Zhiwei et al.

In order to further clarify the mechanism of steam flooding assisted by CO₂ in the heavy oil reservoir, its visualization experiments are carried out by the acrylic plate model and natural cores, and their synergy is analyzed. After the mechanism of synergistic displacement is clarified, the core flow experiments are carried out to further analyze the influence of the synergistic effect and the injection mode on the actual displacement efficiency. The results show that CO₂ assisted steam flooding has the effects of the synergistic viscosity reduction, the expansion of steam sweep efficiency, the availability of residual oil at the blind end, and the demulsification. Among them, the comprehensive viscosity reduction rate of the crude oil is 59.8 %, and the steam sweep area is increased by 37.44 %. Compared to the flooding by steam alone, after the assitant of CO₂, the recovery rate increased significantly. The alternate injection of steam and CO₂ can get a recovery rate of 65.7 %, 7.9 % more than that of mixed injection, and observe the stable foam oil flow at the outlet.

Chukwuemeka Patrick Abbey, Osita Chukwudi Meludu, Adetola Sunday Oniku

Pore pressure is the pressure associated with fluids in the pore spaces of sedimentary rocks. This pressure varies from hydrostatic to severe overpressure. It is classified as abnormal pressure when it deviates from hydrostatic pressure. Incorrect prediction or the absence of pore pressure evaluation can lead to severe damage of the drilling platform, loss of personnel, waste of resources and environmental pollution. This study was carried out in an offshore field in Niger Delta with an objective of predicting the abnormal pressure regime from the seismic volume using seismic inversion technique. First, we employed the Eaton’s and Bower’s model of predicting pore pressure from Well log. The predicted pore pressure from the well was used to calibrate the P-impedance that was used in the inversion process. A pressure-based model for the seismic inversion process was developed. This was constrained by the relationship between the P-impedance and pore pressure in the study area. The predicted pore pressure from the Well logs aligned with the measured pore pressure in the formation. At about 3600 m to end of the Well, depicts a pressure regime that is a deviation from the hydrostatic pressure trend. The abnormal pressure regime is marked by the region where a change is observed in the normal compaction trend line. The cross plot of acoustic impedance against pore pressure reveals a linear relationship; with a direct relationship indicating a normal pressure interval and the indirect relationship at the abnormal pressure regime. The inverted 3D pressure result from the seismic volume validates the normal compaction trend line and also the pressure values estimated from the Well logs. The abnormal pressure regime in the study area is predicted to be found towards the end of Agbada Formation and through the Akata Formation due to the un-compacted shales.

Dong Youzhi, Wen Yacheng, Hou Lei et al.

The structure and operating conditions of the oil storage export filter have different effects on the velocity and pressure distribution of the filter, thus affecting the pressure loss of the filter, prolonging the filtration time and increasing the cost of the manual filter cleaning. To ensure the safe and efficient operation of the filter, the porous medium jump model is used to simulate the boundary of the filter. The three-dimensional numerical simulation of the filter is carried out. The structure and operating conditions affecting the pressure loss of the filter are analyzed. The study results are shown that when the outlet is at the lowest position, the filter has the strongest processing capacity. The flow rate at the bottom of the filter housing is the largest, which can prevent the sludge particles from depositing at the bottom of the housing outside the filter element, thus preventing plugging the filter. As the inlet flow rate increases, the flow rate of the crude oil through the filter element increases. As the mesh size increases, the ability of the crude oil to pass through the filter element decreases. With the viscosity of the crude oil increases, the pressure loss of the crude oil through the filter element increases. The study can provide references for the operation and structure optimization of the filter for crude oil storage export.

Zhi Qingong

CO₂ flooding in low-permeability reservoirs can significantly increase oil recovery. However, owing to the injection of CO₂, the gas content in the production medium is increased, resulting in a decrease in the pump efficiency. To address the problem, a graded pressure subsurface pump is developed. Through the analysis of the structure and working principle of the graded pressure pump, the numerical simulation method is used to simulate the operation of the graded pressure pump in the gas-liquid two-phase medium. The distribution of pressure and gas-liquid two-phase medium and the variation with time in the pump cylinder during the operation of the graded pressure pump is attained. The simulation results indicate that the graded pressure pump can reduce the opening pressure of the travelling valve and lower the stroke loss of the pump. The pressure difference between the travelling valve and the fixed valve can be reduced, and the CO₂ dissolved and precipitated on the upper and lower strokes could be decreased. The up stroke loss is reduced, and the pump efficiency is improved. The graded pressure pump can also avoid the air lock. Compared with the traditional pump, the efficiency of the graded pressure pump can be improved by about 20%, presenting a significant production increase performance.

S. S. Bodunde, P. A. Enikanselu

Abstract Compartmentalization of reservoirs and technical failures experienced in data acquisition, processing and interpretation, without doubt, hinder the effective characterization of reservoirs. In this research, to ensure accuracy, three methods were integrated to characterize reservoirs in SOKAB field. Petrophysical analysis, seismic interpretation, and modeling, and rock physics analysis were utilized. Its objectives were: to develop a template to facilitate improvements in future reservoir characterization research works and producibility determination; to utilize rock physics models to quality check the seismic results and to properly define the pore connectivity of the reservoirs, and to locate the best productive zones for future wells in the field. Forty-three faults were mapped and this included five major faults. Two hydrocarbon bearing sand units (A & B) were correlated across five wells. Structural maps were generated for both reservoirs from which majorly fault assisted and dependent closures were observed. The petrophysical analysis indicated that the reservoirs have good pore interconnectivity (Average Ф effective = 23% & 22% and K average = 1754md & 2295md). The seismic interpretation and modeling alongside the petrophysical analysis were then quality checked via qualitative rock physics analysis. From the K dry/Porosity plot, the sands were generally observed to lie within the lower Reuss and upper Voigt bound which indicates a low level of compaction. From the velocity–porosity cross plot, it was revealed that the lower portions of the reservoirs were poorly cemented and this could hinder their producibility.

E. Karami, T. Jafari Behbahani

Abstract One of the most valuable wastes of the oil industry is oil sludge, found at oil wells, oil pipelines and refineries, and stored in storage units. Oil sludge has many similarities with heavy oil components. This study evaluates the use of oil sludge from the Iranian Oil Pipelines and Telecommunication Company for the manufacture of asphalt. The approximate structure of the oil sludge was analyzed and compared with the structure of conventional bitumen for road construction. Marshall asphalt samples were analyzed according to the American Society for Testing and Materials D1559 0–5–7.5–10–12.5 standard using 15% oil sludge with bitumen and aggregate. To study the physical characteristics of samples of Marshall asphalt, two important tests were performed (1) to determine the pressure resistance, and (2) the relative deformation of examples of all samples. The results showed that asphalt resistance is increased using 25–50% sulfur and 2–7% butadiene styrene polymer. Therefore, Marshall asphalt samples with 30% sulfur were prepared with bitumen and oil sludge. Fifty percent oil sludge in bitumen and a 2% polymer and 15% oil sludge mix with bitumen gave the best results. These mixtures are economically viable.

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<span style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体">为进一步提高大牛地气田单井产量，扩大储量动用程度，应用了水平井尾管回接分段压裂技术。该技术解决了环空间隙小、地层压力低、固井过程易发生井漏和气窜等技术难题；实现双重锚定及封隔，避免了后续分段压裂施工时因固井质量差或常规回接密封失效引起的油套环空封隔失效的风险；压裂回接回收技术能够节省套管，压裂管柱的回收重复利用节约了建井成本。水平井尾管固井回接压裂技术的成功应用，满足了井筒全通径、高承压及可回收的要求，为可钻桥塞分段压裂技术提供了安全可靠的井筒条件，同时保证施工顺利完成，取得较好的改造效果。</span>

胡飚, 朱宏武, 孔祥领 et al.

Based on the natural gas hydrate formation temperature-pressure curve,natural gas hydrate formation in the sleeve valve of subsea tree systems has been analyzed by numerical simulation method.The biggest difference between the actual pressure in sleeve valve and the critical pressure of gas hydrate formation is defined as the maximum equivalent pressure,based on which the effects of inlet temperature,outlet pressure and the relative opening on the maximum equivalent pressure are studied.A new gas hydrate prediction method is proposed——the maximum equivalent pressure method.According to this new method,the critical relative opening degree range of gas hydrate formation has been determined for specific inlet temperature and outlet pressure.Gas hydrate formation in the sleeve valve would not happen in the range of the critical relative opening degree.The results would have great significance for the assurance of natural gas production and transportation.

Kae‐Long Lin, C. Hwang, J. Shie et al.

I. O. Salyer, A. Sircar

Katarzyna Pstrowska, J. Walendziewski, M. Stolarski

I. Alhajri, Y. Saif, A. Elkamel et al.

K. Osathaphan, K. Ruengruehan, R. Yngard et al.

Rajesh N. Patel, P. He, Bo Zhang et al.