Subsurface in situ stress magnitudes from oil-well drilling records: an example from the Venture area, offshore eastern Canada

The mechanical distribution of refracturing rock around well is Considered, the induced stress of vertical fractured well changes in pore pressure is first to establish, taking into account the fluid compressibility, the introduction of the initial artificial fracture fluid factor, an evolution model of in-situ stress is built up for initial fracture. Consider the impact of temperature on the reservoir rock, an evolution model of the temperature induced stress model is built up, Combined with in-situ stress field, an evolution model of Mechanical determination conditions of re-fracture well create new fracture is built up. Calculation of a block of Jilin Oilfield injection wells by the three effects of stress around an oil well, the theoretical calculation results are consistent with the field.

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Analytic and Numerical Solutions of Load and Stress of Casing and Cement in Cementing Section

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.268-270.721 ◽

2012 ◽

Vol 268-270 ◽

pp. 721-724

Author(s):

Zhan Qu ◽

Xiao Zeng Wang ◽

Yi Hua Dou

Keyword(s):

Finite Element ◽

Stress Distribution ◽

Analytical Solutions ◽

Numerical Solutions ◽

Element Model ◽

In Situ Stress ◽

Oil Field ◽

Oil Well ◽

Production Term

With the prolonged production term and the stimulation of the oil well in oil-field, the load which results from the in-situ stress is one of the main reasons to the casing damage. Taking the casing in Cementing section, the cement and the rock surrounding the cement into consideration, a mechanical model is established, while analytical solutions of displacement and stress distribution is obtained. The finite element method is adopted to obtain the numerical solutions of the mechanics model. The result shows that analytical solutions and finite element solutions are approximate. Finite element model of casing/cement/formation which is established in the paper can be used to analyze the load and stress distribution of worn casing with non-uniform in-situ stress.

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Subsurface in situ stress magnitudes from oil-well drilling records: an example from the Venture area, offshore eastern Canada

Canadian Journal of Earth Sciences ◽

10.1139/e87-167 ◽

1987 ◽

Vol 24 (9) ◽

pp. 1748-1759 ◽

Cited By ~ 25

Author(s):

W. B. Ervine ◽

J. S. Bell

Keyword(s):

Feed Rate ◽

Fluid Pressure ◽

Sedimentary Basins ◽

In Situ Stress ◽

Depth Interval ◽

Principal Stresses ◽

Eastern Canada ◽

Stress Regime ◽

Clastic Rocks

This report describes a method of obtaining information on in situ stress magnitudes at depth in sedimentary basins by using information gathered while drilling oil wells. If we assume that one of the principal stresses is vertical at a well site, principal stress magnitudes can be estimated in the following manner. Sv is equated with overburden load, which is obtained by integrating density log records. SHmin is equated with leak-off test pressures measured over short open-hole intervals and also from selected initial feed-rate pressures. SHmax is derived from the equation SHmax = 2P1 − P0, where P1 is the leak-off pressure or the initial feed-rate pressure, and P0 is the fluid pressure over a specified depth interval. This relationship is a simplified approximation of Hubbert and Willis' well-known equation Pb = T + 3SHmin − SHmax − P0, describing hydraulic fracturing around a borehole.Using this approach, stress magnitudes were estimated for 44 depth intervals in four wells drilled over the Venture structure on the Scotian Shelf, offshore eastern Canada. The information obtained between subsea depths of 815 and 5783 m provides a consistent record and points to a stress regime where SHmax > Sv > SHmin. At approximately 6000 m, Sv and SHmin may become equal. Inferred stress magnitudes in the upper 3000 m are comparable to those measured in clastic rocks in western Canada.

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The Stress Distribution and Calculation of the Different Zone of Wellbore Surrounding Rock Based on the Damaged Theory

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.1052 ◽

2012 ◽

Vol 170-173 ◽

pp. 1052-1055

Author(s):

Wan Chun Zhao ◽

Chen Yan Sun ◽

Ting Ting Wang ◽

Yu Liu ◽

Cai Ping Yang

Keyword(s):

Stress Distribution ◽

Stress Field ◽

In Situ Stress ◽

Surrounding Rock ◽

Oil Well ◽

Damage Area ◽

Stress Direction ◽

The Stability ◽

Adjacent Rock

In order to describe the stability of borehole face and the theory of hydraulic fracture fissure stretch in real, the stress field of adjacent rock in the hole should be constituted exactly .The article is based on the damnification dynamics theory, meanwhile, considered the rock is fracture-pore dual medium and the damnification characteristic of the rock in hole .Adjacent formation is sectioned three areas: damage-area, damnification-area, elasticity-area. And we have calculated the ambient stress distribution of one oil-well .The results show that the destructive radius of the minimum in-situ stress direction is 1.247m, the damage radius is 8.082m, the destructive radius of the maximum in-situ stress direction is 0.998m, and the damage radius is 6.5865m.

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