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Method research of determining production layer dynamic permeability by production logging data of the oilfield

SONG Hong-wei,ZHANG Chang-min,GUO Hai-min,DAI Jia-cai,WU Yuan,

地球物理学进展 , 2009,
Abstract: At present, average producing water percentage of the oilfield during mid-later period is more than 80% in our country. Therefore it is very important to estimate production layer and determine planar distributions of reservoir dynamic permeability and press and residual oil. Based on the radial flow equation analyses, the relation between reservoir permeability and produced liquid rate/water absorption, and bottom hole flowing pressure alteration are studied, a method to estimate dynamic permeability of each production layer by production logging data of the oilfield is proposed. This method doesnot need to close wells, and can reduce cost. The result can reflect well the characteristics of produced fluid of each production layer.
Sparse Spike Inversion Predicts Lateral Variation of Porosity La méthode Sparse Spike Inversion de prévision des variations latérales de porosité  [cached]
Alam A.,Ardali A.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1990022
Abstract: The sparse spike inversion method estimates from deconvolved seismic data that reflectivity which has the minimum sum of absolute values subject to two constraints. First, the reflectivity spectrum matches the seismic data spectrum over a specified bandwidth. Second, the impedance function resulting from integration of the reflectivity passes through a set of impedance windows, specified at interpreted horizon times. We use an interactive workstation to identify the phase of the residual wavelet, set horizon impedance constraints and monitor impedance of a large data set run in batch mode. The result is a laterally continuous estimate of the impedance function. The 1989 EAEG Inversion Workshop provided a 2-D, relative-amplitude-processed stack section. A limestone reservoir with an average reflection time of 890 ms and a temporal thickness of about 20 ms appears on the stack as an event with a laterally changing waveform and amplitude. These changes are considered to be a result of the interference between reflections from the top and bottom of the reservoir which has laterally varying porosity and thickness. Four wells are located on this line, but the impedance log for Well 1 was the only one supplied to calibrate the inversion. Other wells were blind , i. e. those wells for which logs were unavailable prior to the inversion workshop. The object of the study was to delineate the reservoir and predict impedances and porosities in the three blind wells. We applied the sparse-spike method to the stack section. The interpretation of thickness and impedance from the estimated impedance section agreed with, the lithologic description of the reservoir presented by organizers during the workshop. Also, the wall-to-wall relative variations of estimated impedance in the reservoir followed the pattern of actual impedance variation among the known well and the three blind wells. After the workshop, we used the porosity for Well 1 to perform a porosity prediction experiment. Assuming that for a common rock type we could derive the porosity from impedance, we calibrated the lithologic and pore fluid parameters such that the derived porosity at Well 1 is 5 %, i. e. the value published by the workshop organizers. The porosity profile for the entire line, derived from the calibrated parameters and estimated impedance profile, predicted the actual porosities for Wells 2, 3, and 4. La méthode Sparse Spike Inversion (SSI) part de données sismiques déconvoluées pour estimer une trace impulsionnelle telle que la somme de ses valeurs absolues soit minimale et qu'elle soit so

NIE Jian-Xin,YANG Ding-Hui,YANG Hui-Zhu,

地球物理学报 , 2004,
Abstract: The Biot-flow mechanism and the squirt-flow mechanism are the two most important mechanisms of pore fluids in a fluid-saturated porous medium.Based on the BISQ model including the two mechanisms simultaneously,we perform the inversion of reservoir parameters (e.g.,porosity,permeability,and saturation) by using the Niche genetic algorithms (NGA).Numerical experiments indicate that during the process of reservoir parametric inversion the convergence of objective function is speedy,and our algorithms have the property of strongly protecting noises of observations.The results of reservoir parametric inversion are very precise while the errors of observation are less than 5%.Finally,applying to the practical inversion of experimental data proves that our algorithms are effective for the inverse problems of wave propagation in partially saturated reservoir media affected simultaneously by the Biot and squirt-flow mechanisms.
Effects of Engineering and Geology Factors on Oil-Water Flow Regularity in Sandstone Reservoir with Bottom Water Drive  [PDF]
Mingkun Zhai, Gaoming Yu, Yizhong Zhang, Chenchen Wang
Open Journal of Yangtze Oil and Gas (OJOGas) , 2018, DOI: 10.4236/ojogas.2018.34021
Abstract: The aim of this paper is to solve the problems such as complex morphology of water cone and ridge, as well as out-of-control flooding resulting from the abundant natural energy, formation heterogeneity and irregular inter-bed distribution. In this paper, the numerical simulation technique combined with the orthogonal experimental design method is applied to study the factors of engineering and geology that affect the oil-water flow regularity on Tahe sandstone reservoir with bottom water, such as reservoir permeability, liquid production rate, interlayered property and scale and location, liquid production rate, length of horizontal well etc. Results show that reservoir permeability, inter-layer and liquid production rate are key factors that influence the performance of coning and ridging water; the optimal lengths of horizontal wells change with different permeability formation. Besides, inter-layer physical properties also play an important role in the vertical well location. This study could provide theoretical and technical guidance for the early well spacing, the technical strategy of development as well as measures for water control and stability in sandstone reservoir with bottom water.
Residual moveout correction and Poisson''s ratio inversion

WANG Yun-zhuan,YANG Li-wei,LI Su-hua,

地球物理学进展 , 2005,
Abstract: The Poisson's ratio inversion formula is derived from Shuey reduced equation which stresses Poisson's ratio change. Residual moveout correction to seismic data will make the change trend of the amplitude versus offset (or incident angle) more obvious before Poisson's ratio inversion. It can improve the precision of inversion. Though the treatment to theory models and real data, this inversion method is proved practicable. Low Poisson's ratio anomalies can be predicted and natural gas can be found from inversion results.
A geoacoustic inversion method based on bottom reflection signals

Yang Kun-De,Ma Yuan-Liang,

物理学报 , 2009,
Abstract: It is important for underwater acoustic modeling and passive localization to estimate the geoacoustic properties with high accuracy. A geoacoustic inversion scheme was presented, which uses a broadband source to generate the linear frequency-modulated signal at different ranges and depth. The signal was received by a vertical array. The bottom reflection loss was extracted by matched filtering and then used to estimate the sea-bottom density and sound speed. Meanwhile, an inversion method based on sub-bottom reflection was investigated using the experimental data. Because the direct arrivals in the water were influenced strongly by the internal waves, the first sea-bottom reflection was taken as the reference path to calculate the relative arrival time and amplitude of sub-bottom reflections. Firstly the sediment sound speed and thickness were estimated using different source depth and receiver depth. Then the sediment attenuation was estimated by assuming that it has linear frequency dependence. The estimated values of the sediment properties compared well with the core data, chirp sonar data, and the matched field inversion results.
The Influences of Multi-exponential Inversion on Relaxation Time Spectrum of Rocks  [PDF]
Wang Qingyi,Yin Quan,Liu Yang,Luo Hui
Information Technology Journal , 2013,
Abstract: Theoretical and practical research results both indicate that the induced polarization decaying curve of rocks has a close relationship with the pore structure and permeability of stratum in oil well logging. For better evaluating the reservoir characteristic from the induced polarization decaying data, the influence of parameters on inversion results should be analyzed in relaxation time spectrum. In this paper, the least square fitting method with penalty item is adopted to implement the multi-exponential inversion using the secondary field data of rocks, the continuous and smooth relaxation time spectrum is therefore obtained. The influence of the factors such as numbers of distribution points, relaxation time distribution, smooth factors, signal and noise ratio (SNR) on the spectrum are analyzed in detail. The results show that the penalty inversion may achieve good effect while the SNR is larger than 20 and the distribution points are between 32 and 64.
Effect of Polymer Adsorption on Permeability Reduction in Enhanced Oil Recovery  [PDF]
Saurabh Mishra,Achinta Bera,Ajay Mandal
Journal of Petroleum Engineering , 2014, DOI: 10.1155/2014/395857
Abstract: In order to reduce the permeability to water or brine, there is a possibility of polymer injection into the reservoir. In the present work, special focus has been paid in polymer [partially hydrolyzed polyacrylamide (PHPA)] injection as a part of chemical method. Tests were conducted in the laboratory at the ambient temperature to examine the reduction in permeability to water or brine in the well-prepared sand packed after the polymer injection. The experiments were performed to study the effect of polymer adsorption on permeability reduction by analyzing residual resistance factor values with different concentrations of polymer solutions. The rheological behavior of the polymer has also been examined. The experimental results also indicate that the adsorption behavior of polymer is strongly affected by salinity, solution pH, and polymer concentration. To investigate the effect of polymer adsorption and mobility control on additional oil recovery, polymer flooding experiments were conducted with different polymer concentrations. It has been obtained that with the increase in polymer concentrations, oil recovery increases. 1. Introduction With reservoir getting matured, the increased water production with producing oil is a major concern in the petroleum industry. Hydrocarbon production decreases, which affects recovery economics and disposal of the excessive high amount of underground water, which causes complex environmental problems [1]. Oil and gas reservoirs are often heterogeneous, having a different permeability in different-different layers. This causes channelling of excessive water production through high permeability layers, as a result of which large amount of movable oil and gas remains trapped in low permeability zones which results in poor recovery in primary and secondary stages of production. A significant part of the residual oil can be recovered by application of a polymer solution in the heterogeneous reservoirs [2]. The excess water production can be controlled without affecting oil production rate by using polymer to reduce the relative permeability to water more than the relative permeability to oil [3]. The injection of polymer solutions in production wells has proven to be an effective method to reduce or block excessive water production [4]. In a water-wet reservoir, oil flows inside pores while water through the annulus between the pore walls and the oil-water interface [5]. When the polymer solution is injected, it gets adsorbed on the rock surface to form a thin layer. As water flows through this zone, the adsorbed polymer
Historical Evolution of the Trophic and Limnological Relationships in the Itaipu Reservoir: Top-Down and Bottom-Up Effects upon Fish Production  [PDF]
Rinaldo Antonio Ribeiro Filho, Miguel Petrere Junior, ?ngelo Antonio Agostinho, Simone Friderigi Benassi, Julia Myriam de Almeida Pereira, Edson Kiyoshi Okada
Advances in Bioscience and Biotechnology (ABB) , 2015, DOI: 10.4236/abb.2015.66039
Abstract: Many experimental studies have contributed to the development of the theory of trophic chains in lacustrine habitats. They have revealed the important role played by fish, a subject that has been mostly ignored by limnological studies for the past few decades. Most of these studies were developed in Europe and in the United States. The general applicability of this theory has not yet been tested in subtropical and tropical habitats. In spite of controversies, the bottom-up: top-down trophic cascade hypotheses are the most adopted conceptual models. In this context, we examined if these hypotheses may be corroborated by data from the subtropical Itaipu Reservoir. A negative effect was verified between water transparency and total suspended solids. The detritivorous fish exerted a controlling effect on chlorophyll-a concentrations. Bottom-up effects were detected in four trophic levels, and top-down was detected in just one trophic level. The limnological variates influenced the chlorophyll-a concentration, which indicated that the lnTKN plus the effect of the quarter and the reservoir zone (and their interaction) were important.
Experimental Study on Influencing Factors of Resistance Coefficient and Residual Resistance Coefficient in Oilfield Z  [PDF]
Xinran Wang, Lizhen Ge, Dong Liu, Qin Zhu, Bin Zheng
World Journal of Engineering and Technology (WJET) , 2019, DOI: 10.4236/wjet.2019.72018
Abstract: In order to clarify the major influence factors of resistance coefficient and residual resistance coefficient, so as to provide the basis for optimizing the polymer flooding schemes in oilfield Z of Bohai Sea, artificial cores were made by simulated the characteristic parameters of real reservoir and the spacing of production-injection wells. The main parameters considered include reservoir permeability, polymer solution concentration and polymer injection rate. Core experiment of polymer flooding was taken by considering all the main parameters. The result showed that resistance coefficient and residual resistance coefficient decrease with the increase of core permeability. Resistance coefficient and residual resistance coefficient increase with the increase of concentration of polymer solution. The increment of displacement pressure in low permeability core is higher than in medium and high permeability core. The resistance coefficient increase with higher displacing velocity, and the increment in high permeability core is higher than in low permeability?core. The displacement velocity has little effect on the residual resistance coefficient. The experimental results can effectively guide the formulation of polymer flooding scheme in offshore oilfields, and optimize the appropriate injection rate and concentration of polymer solution for different properties of reservoirs, thus ensuring the effectiveness of polymer flooding in offshore oilfields.
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