Effect of Oil and Gas Saturation on Simulation of Temperature History and Maturation

Author(s):  
H. S. Poelchau ◽  
C. Zwach ◽  
Th. Hantschel ◽  
D. H. Welte
Geophysics ◽  
1958 ◽  
Vol 23 (3) ◽  
pp. 459-493 ◽  
Author(s):  
M. R. J. Wyllie ◽  
A. R. Gregory ◽  
G. H. F. Gardner

An experimental investigation has been made of the factors which affect the velocity of vibratory signals in porous media. It is shown from the results of experiments carried out on appropriate natural and synthetic porous systems that the time‐average formula previously suggested by Wyllie, Gregory, and L. W. Gardner is of considerable utility. This formula states that [Formula: see text] where [Formula: see text] measured, [Formula: see text] in saturating liquid, [Formula: see text] in rock solid, and ϕ=volumetric porosity fraction. The effects are examined of differential compacting pressures on the applicability of this formula to consolidated and unconsolidated rocks. It is shown that the time‐average relationship cannot be applied to determine the total volumetric porosity of carbonate rocks which are vugular and fractured. In such rocks, paradoxically, this circumstance may be advantageous because of the lithological information that may be obtained from an appropriate combination of velocity and nuclear log data. The effects of oil and gas saturation on velocity have been examined experimentally and are found to be comparatively minor. The combination of velocity data with information from electric logs in order to locate zones of oil and gas saturation is shown to be generally valuable; this is particularly so when holes are drilled with oil‐base mud. Some discussion is given of the possible effects on velocity measurements of the relative wettability of rock surfaces by various liquids. Owing to instrumental limitations, it cannot necessarily be assumed that measurements made in the laboratory are directly applicable to the interpretation of velocity data obtained under field conditions.


2019 ◽  
Vol 2 (1) ◽  
pp. 133-140
Author(s):  
Dmitry Novikov

The results presented in the work were obtained in the studies of the features and zonality of water-dissolved gases within the boundaries of the oil-and-gas bearing sediments of the Nadym-Taz interfluve. Methane-containing waters with total gas saturation from 0.3 to 5.7 l/l and average CH4 content from 95.5 vol.% in the Aptian-Albian-Senomanian complex to 83.3 vol.% in the Lower and Middle Jurassic complex are developed in the region. With an increase in the depth, an increase in the content of homologues ΣHС (C2H6, C3H8, C4H10, C5H12 and C6H14) occurs from 1.34 vol.% in the Aptian_Albian-Senomanian complex to 11.67 vol.% in the Lower and Middle Jurassic complex. The maximal concentrations of ΣHС up to 30 vol.% were revealed in the lower part of the Neocomian complex in the marginal waters of oil deposits. An increase in CO2 content and a regular decrease in the ΣHС/N2 ratio from 96 in the Aptian-Albian-Senomanian complex to 52 in the Lower and Middle Jurassic complex are observed with an increase in the depth.


2014 ◽  
Vol 05 (04) ◽  
pp. 224-232
Author(s):  
O. G. Nusratov ◽  
G. G. Abdullayeva ◽  
I. A. Ismayilov

Author(s):  
N. A. Skibitskaya ◽  
◽  
I. O. Burkhanova ◽  
M. N. Bolshakov ◽  
V. A. Kuzmin ◽  
...  

Evaluation of rock wettability is an important task, since this parameter determines the distribution of water and oil in the reservoirs and their relative and phase permeability. The reliability of evaluation the wettability of rock samples depends on the drilling-in conditions during core sampling and core sample preparation methods. The investigation of the surface properties of the core from the Orenburg oil and gas condensate field showed that using of polymer-colloidal drilling mud leads to hydrophilization of the samples' surface. To obtain information on the actual wettability values of rock samples taken from wells drilled with polymer-colloidal drilling mud a method for estimating the relative (predominant) wettability of rocks based on petrophysical and lithological studies data is proposed. The authors suggest that the extraction of oil and gas source rock samples leads to irreversible changes in surface properties that cannot be restored. Keywords: selective wettability; relative wettability; predominant wettability; polymer-colloidal drilling mud; residual gas saturation; trapped gas saturation; pore space structure; extraction.


10.2118/90-pa ◽  
1961 ◽  
Vol 1 (04) ◽  
pp. 254-258 ◽  
Author(s):  
J. Naar ◽  
R.J. Wygal

Abstract An equation for three-phase (water, oil, gas) imbibition oil permeability is developed, assuming the water to be the dominant wetting fluid. Oil isoperms are obtained for consolidated sandstones characterized by. The evolution of an oil-gas system imbibing water from is shown to proceed along a line of constant oil saturation with increasing oil permeability and decreasing gas saturations. When the gas saturation cannot be reduced further, the system evolves along a line of constant with decreasing oil saturation and permeability. The initial gas saturation is shown to reduce markedly the effect of complete wetting by either oil or water on flow performance. Introduction Imbibition oil isoperms are required for performance prediction when a well is producing water, oil and gas. This situation occurs in multiphase displacements such as underground combustion, steam injection and the water flooding of highly depleted reservoirs. In a recent paper, a model was presented for the prediction of two-phase imbibition characteristics. This paper extends the imbibition model to the case of three phases by assuming that the water is the dominant wetting fluid. The following results were obtained from the model:an analytical expression of oil isoperms;oil isoperms as functions of reduced water, oil and gas saturations, valid for all sandstones having a capillary pressure curve which can be approximated by; andevaluation of the three-phase flow performance as dictated by complete wetting by either oil or water. The agreement between predicted and observed oil recovery in the presence of a gas phase, reported in Ref. 1, is a partial support for the present development. However, experimental data are not available at this time to check fully the model predictions. Perhaps this paper will stimulate the collection of such data. THEORETICAL The imbibition model of a porous medium has been described previously, and the reader is referred to the paper of Naar and Henderson for details. In brief, the model is formed by the random interconnection of straight capillaries, with a provision for the blocking of the non-wetting phase by the invading wetting fluid.


Georesursy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 40-48 ◽  
Author(s):  
Renat Kh. Muslimov ◽  
Irina N. Plotnikova

The article is devoted to the problem of replenishing of oil reserves and considers it (the problem) in the aspect of deep degassing of the Earth. Based on an analysis of the results of a long-term study of the Precambrian crystalline basement in the territory of Tatarstan and adjacent areas, a number of new criteria are formulated that allow us to identify the processes of deep degassing of the Earth within the studied region. The article provides a brief overview of current views on the problem of replenishing oil reserves, considers options for possible sources and the mechanism of replenishment of hydrocarbons in the developed deposits. The arguments in favor of the modern process of deep degassing within the South Tatar arch and adjacent territories are examined, which are unequivocally confirmed by: the dynamics of the hydrochemical parameters of the deep waters of the crystalline basement obtained in the monitoring mode at five deep wells; uneven heat flux and its anomalies, recorded according to many years of research under the guidance of N.N. Khristoforova. The degassing processes are also confirmed by the dynamics of gas saturation of decompressed zones of the crystalline basement recorded in well 20009-Novoelkhovskaya, the dynamics of gas saturation of oil of the sedimentary cover and the composition of the gas dissolved in it, identified by oil studies in piezometric wells located in different areas of the Romashkinskoye field; the seismicity of the territory of Tatarstan, as well as its neotectonic activity. As criteria proving the existence of a process of replenishing the reserves of the developed oil fields of the South Tatar Arch, the features of the deep structure of the earth’s crust according to seismic data, as well as the results of geochemical studies of oils are considered.


Kappa Journal ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 240-249
Author(s):  
Muhammad Zuhdi ◽  
◽  
Jannatin Ardhuha ◽  
Kosim Kosim ◽  
Wahyudi Wahyudi ◽  
...  

The 4D microgravity method is a development of the gravity method with the time as the fourth dimension. This research was conducted to find a better way of interpreting the 4D gravity anomaly due to fluid injection around the reservoir. Researchers used GRABLOX for the interpretation of 4D anomalies around the reservoir. The results of the inversion of field data using GRABLOX provide the value of the injection fluid infiltration volume, which shows the distribution of the injection fluid movement on the reservoir. Another physical parameter that can be generated from GRABLOX with a modified value is the reduction in oil and gas saturation due to fluid injection. The inversion results using GRABLOX in the field data indicate a change in reservoir rock density up to 0.28 gr/cc associated with a reduction in gas and oil saturation. The reduction in gas saturation due to the injection fluid has the smallest value of 0% and the largest is up to 66%. The reduction in oil saturation only contributes to a density change of 20% of the reduction in gas saturation. The results of the GRABLOX trial on synthetic data and field data show that both can provide an identification of the movement of the injection fluid in the reservoir, as well as provide other physical parameters, ie. the reduction in oil saturation due to fluid injection.


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