IOSR Journal of Engineering (IOSR-JEN) Volume 5 Issue 5 Version 2

Fluvial meander belt sediments form some of the most architecturally complex reservoirs in hydrocarbon fields due to multiple scales of heterogeneity inherent in their deposition. Currently, characterization of meander belt bodies largely relies on idealized vertical profiles and a limited number of analogue models that naively infer architecture from active river dimensions. Three-dimensional architectural data are needed to quantify scales of grain-size heterogeneity, spatial patterns of sedimentation and bar preservation in a direct relationship with the relevant length scales of active river channels. In this study, three large flume experiments and a numerical model were used to characterize and construct the architecture (referred to as 'archimetrics') and sedimentology of meander belt deposits, while taking reworking and partial preservation into account. Meander belt sandbody width-to-thickness ratios between 100 and 200 were observed, which are consistent with reported values of natural meander belts. For the first time, the relief of the base of a meander belt is quantified, enabling improved estimates of connectedness of amalgamated meander belts. A key observation is that the slope and number of lateral-accretion packages within natural point bar deposits can be well predicted from fairly basic observ-ables, a finding subsequently tested on several natural systems. Probability curves of preserved architectural characteristics for three dimensions were quantified allowing estimates of bar dimensions, baffle and barrier spacing distributions and container dimensions. Based on this, a set of rules were identified for combining reservoir parameters with the identified probability curves on sand-body dimensions and character, to help create more realistic geomodels for estimating exploration success on the basis of seismic and core data.

River valleys experiencing active tectonic controls bear typical geomorphic signatures. If incidentally, the valley concerned is highly petroliferous and oil habitat is strongly governed by tectonic forcings; expectations grow among the explorers from the recently developed disciplines like remote sensing methods to play a meaningful complementary role. However, when the rate of sediment influx is very high, a competitive damping effect sets in that obliterates many important geomorphic signatures. Thus, in spite of highly potential remote sensing techniques capable of offering different filtering options for suitable image processing, the anticipated breakthroughs in 'exploration leads' might not be achieved. Under such circumstances, it is observed that shallow subsurface data like uphole and shallow seismic refraction, which provide a highly representative description of near surface lateral inhomogeneities, are very useful. Work was done on high density shallow refraction data sets in Namrup-Sapekhati window, situated in the south bank of the upper reach of the Brahmaputra valley, Assam. Three parameters namely; lateral variations in the P-wave velocities of the topmost low velocity layer (LVL) and the layer following immediately, known commonly as sub-weathered zone and the thickness of the LVL were considered. A new approach " Multiparametric microzonation " was applied to implement a zonation scheme based on different combinations of the above said parameters in the GIS based environment and oil field locations along with some of the geological elements like blind faults were collated. It was observed that high velocity (both top and bottom layers) and thicker LVL bearing zones are more closely associated with the oil fields.

Journal of Geochemical Exploration, 2006

A method to quantitatively estimate residual or palaeo-oil column heights is proposed using criteria based on the presence or absence of oil shows in a single heterogeneous reservoir rock sample. The residual or palaeo-oil column height below the sample is constrained through the determination of the displacement pressure of regions in the sample containing oil shows (Pd-o) and the displacement pressure for regions that are devoid of any evidence of oil shows (Pd-w). The height of the residual or palaeo-oil column below the sampling depth can then be estimated to be greater than the equivalent height corresponding to Pd-o, but less than the height corresponding to Pd-w. Three examples from two basins in China were investigated using the method to determine their residual and palaeo-oil column heights.

Sedimentary rock is a type of rock that is formed by sedimentation of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, mass movement or glaciers.

International Journal of Surface Mining, Reclamation and Environment, 1990

ABSTRACT OILSAND is a computer software system designed to perform all steps required for the geostatistical modelling, display, and preliminary evaluation of the in-situ reserves of an oil sand deposit. The system allows the integration of geological control descriptions with the techniques of ordinary kriging and conditional simulation. In addition, it permits the consideration of the mining method in the calculation of reserves and associated estimation variance. OILSAND consists of five main and three display programs in standard FORTRAN code. The main programs (a) calculate statistics of the input data; (b) generate two and/or three dimensional grids of kriged and/or conditionally simulated variates; and (c) perform volumetric calculations. Display programs are used to display data statistics and cross-sectional representations of grided three-dimensional block models of a deposit.

Journal of Geography and Geology

This paper investigates the reservoir architecture of thin interlayer within meandering river monosandbody in the thick-bedded oil layers. The thin interlayer within the monosandbody of the terrestrial reservoir is one of the dominant factors which form the reservoir heterogeneity of fluid motion. It is of equal importance in comparison with the rhythmic distribution of permeability, and it is also the important content of the elaborate representation of reservoirs. However, previous researches of the heterogeneity of reservoir focus mostly on the theory of distribution disparity of the permeability and neglect the influence of thin interlayer on the heterogeneity. Therefore, taking the PⅠ2 individual reservoir at the Putaohua reservoir formation in Daqing oilfield as an example, this paper analyzes the distribution, formation, and the three-dimensional construction of the internal thin interlayer of the monosandbody from a new point of view, on the basis of which a set of cycle res...

This paper considers the modelling and upscaling of small scale patchy cements and evaluates the influence on oil-in-place calculation in a Triassic braided fluvial reservoir. The modelling method replicates the precipitation of cements over a background depositional facies. The detailed modelling on the transition zone where effective porosity may be low but saturation may be higher than expected in the uncemented matrix is the reason for teh increase in oil-in-place in a field-scale study.

2020

Original oil in place is most critical stages of reservoir management, where the economic advantage of the reservoir is evaluated by estimation of the petrophysical properties and oil reserves. This work was carried out in five wells of Nasiriya oilfield, which is one of the Iraqi oil fields in the southern region. The aim of this study is to calculate oil in place from available data in Nahr Umar formation, having a complex lithology by two methods (static and simulation). It was found that the static model used for computing the petrophysical distribution oil in place was equal to (114 MM or 716 MM STB) and 117 MM or 734 MM STB for the dynamic one.

This case study involves sand distribution prediction for the Gujiazhi and Houwujiahu gas fields in Jilin Province, China. Initial data analysis involved correcting and calibrating the well logs. Log data from 74 wells were available from the Gujiazhi field and the Houwujiahu field. This initial process also established 3-D porosity, permeability and clay volume models for each field. The Gujiazhi grid has a cell dimension of 100x100x2 meter, Houwujiahu grid 100x100x1 meter.

2020

Interpretation of Multicomponent Seismic data, as compared to traditional 3D Seismic studies, requires integration of PP & PS seismic data. In the last few years Multicomponent Seismic Interpretation studies have contributed to exploratory success and reservoir characterization in a few fields of Cambay Basin, as well as in a few other basins in India. An integrated approach based on reservoir performance analysis, observed fluid contacts in wells, local area contacts from well performance data and joint inversion data along with seismic driven petrophysical models was followed to identify zones of residual oil in the GS-9 pay in the area around well G#DD. Inversion output attributes were correlated with well sand thickness, and a relationship was established between the two. This relationship was used to populate the well property in the study area to generate sand isolith maps. Likewise, other petrophysical parameter maps (Heff, Sw, Vclay) were prepared to characterise the reservo...