In:
Interpretation, Society of Exploration Geophysicists, Vol. 10, No. 3 ( 2022-08-01), p. SD47-SD59
Abstract:
With the development of the global shale oil and gas revolution, shale oil has became an important replacement field to increase oil and gas reserves and production. The Chang 7 member of the Yanchang Formation in the Ordos Basin is an important shale oil exploration series in China. To study the micropore-throat structure characteristics of the Chang 7 member, we have conducted nuclear magnetic resonance (NMR) and high-pressure mercury intrusion (HPMI) experiments to analyze the pore-throat structure features of the Chang 7 reservoir, and we have considered fractal theory to study the fractal characteristics. The NMR results indicate that the [Formula: see text] spectral morphology of the Chang 7 reservoir can be characterized by three main patterns encompassing early and late peaks with different amplitudes: the type 1 reservoir contains mostly small pores and few large pores, and the porosities of the small and large pores range from 4.16% to 9.04% and 0.70% to 2.40%, respectively; the type 2 reservoir contains similar amounts of small and large pores; and the type 3 reservoir contains few small pores and mostly large pores, while the porosities of the small and large pores range from 1.81% to 2.74% and 3.32% to 5.64%, respectively. The pore-throat structure parameters are obviously affected by the pore size distribution, which in turn influences the reservoir seepage characteristics of the reservoir. The micropore-throat structure of the reservoir exhibits obvious piecewise fractal characteristics and mainly includes dichotomous and trilateral fractals. The type 1 reservoirs are dominated by dichotomous fractals, and these two fractal types are equally distributed in the type 2 and 3 reservoirs. The fractal dimension of the pore throats of different scales exhibits a negative correlation with the corresponding porosity, but no correlation is observed with the permeabilit y, indicating that the size of the reservoir determined by pore throats imposes a strong controlling effect on their fractal characteristics.
Type of Medium:
Online Resource
ISSN:
2324-8858
,
2324-8866
DOI:
10.1190/INT-2021-0162.1
Language:
English
Publisher:
Society of Exploration Geophysicists
Publication Date:
2022
detail.hit.zdb_id:
2741968-X
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