Description of fracture zones based on the structural inhomogeneity of the reflector deformation field

Abstract

The role of fracture and faulting zones in the filtration inhomogeneity of productive formations in oil and gas fields has been considered. The absence of fracture or faulting zones from geological and, consequently, hydrodynamical models reduces the flooding efficiency and the oil recovery factor in general. The current situation results from the underdevelopment of methods for the mapping and classification of fracture zones based on seismic-prospecting data. For example, the use of the seismic-horizon gradient method makes it possible to describe only complete rock fracturing at tectonic-block boundaries. We propose to use the structural inhomogeneity of the deformation field of seismic horizons for a more complete description and classification of fracture zones by the faulting regime. This parameter is suitable not only for late but also for early stages of faulting and describes block-boundary deformations more accurately than gradients. The example of a West Siberian oil and gas field showed that the production wells from the J1 productive formation in the faulting zones with the calculated post-Cenomanian structural inhomogeneity of the deformation field have considerably higher discharges owing to fracture permeability.

Tectonophysical approach to the analysis of geological and geophysical data on gas-condensate deposits with the complex platform cover

“…17, а) в отличие от тектонически активных областей, где блоки обычно полностью ограничены разрывными структурами по периметру [Sherman et al, 1999;Gatinsky, Rundquist, 2004;Seminskii, 2008]. Подобный характер делимости был ранее установлен для осадочного чехла на ряде нефтяных месторождений Западной Сибири [Glukhmanchuk, Vasilevskiy, 2013], однако в качестве активных сегментов дизъюнктивной сети выступали лишь отдельные участки зон трещиноватости. Замкнутость разрывной сети, наряду с вложением мелких блоков в более крупные, свидетельствует о существовании строгой иерархической соподчиненности элементов ЗБС.…”

Fracture prediction in the tight-oil reservoirs of the Triassic Yanchang Formation in the Ordos Basin, northern China

“…Various factors, such as the proximity of faults, the curvature of folds, the layer thickness and the lithology, are deemed to control the fracture development in tight reservoirs (e.g., Ju et al 2013), and the anisotropy or heterogeneity should also be considered in the modeling (e.g., Glukhmanchuk and Vasilevskiy 2013). However, it is difficult for 2D geomechanical models to fully consider all these factors, and the modeling results cannot be used successfully for exploration and production.…”