Workflow For Pore Pressure And Horizontal Stress Field Estimation In Vertical Wells Using Well Data In The "X" Field In South Sumatra

2018 ◽  
Author(s):  
Zulfikar Simatupang
Keyword(s):  
Stress Field ◽  
Pore Pressure ◽  
Horizontal Stress ◽  
Vertical Wells ◽  
Field Estimation ◽  
Well Data

THE OTWAY BASIN: EARLY CRETACEOUS RIFTING TO NEOGENE INVERSION

1995 ◽  
Vol 35 (1) ◽  
pp. 494 ◽  
Author(s):  
A.J. Buffin ◽  
A.J. Sutherland ◽  
J.A. Gorski
Keyword(s):  
Stress Field ◽  
Normal Fault ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
Natural Fracture ◽  
Water Flooding ◽  
Hydraulic Fractures ◽  
Vertical Wells ◽  
Minimum Horizontal Stress ◽  
Maximum Horizontal Stress

Borehole breakouts and hydraulic fractures in­ferred from dipmeter and formation microscanner logs indicate that the minimum horizontal stress (σh) is oriented 035°N in the South Australian sector of the Otway Basin. Density and sonic check-shot log data indicate that vertical stress (σv) increases from approximately 20 MPa at a depth of one km to 44 MPa at two km and 68 MPa at three km. Assum­ing a normal fault condition (i.e. σy > σH > σh), the magnitude of σh is 75 per cent of the magnitude of the maximum horizontal stress (σH), and the magni­tude of σH is close to that of av. Sonic velocity compaction trends for shales suggest that pore pressure is generally near hydrostatic in the Otway Basin.Knowledge of the contemporary stress field has a number of implications for hydrocarbon produc­tion and exploration in the basin. Wellbore quality in vertical wells may be improved (breakouts sup­pressed) by increasing the mud weight to a level below that which induces hydraulic fracture, or other drilling problems related to excessive mud weight. Horizontal wells drilled in the σh direction (035°N/215°N) should be more stable than those drilled in the σH direction, and indeed than vertical wells. In any EOR operations where water flooding promotes hydraulic fracturing, injectors should be aligned in the aH (125°N/305°N) direction, and off­set from producers in the orthogonal σh direction. Any deviated/horizontal wells targeting the frac­tured basement play should be oriented in the σh (035°N/215°N) direction to maximise intersection with this open, natural fracture trend. Hydrocar­bon recovery in wells deviated towards 035°N/215°N may also be enhanced by inducing multiple hydrau­lic fractures along the wellbore.Considering exploration-related issues, faults following the dominant structural trend, sub-paral­lel to σH orientation, are the most prone to be non-sealing during any episodic build-up of pore pres­sure. Pre-existing vertical faults striking 080-095°N and 155-170°N are the most prone to at least a component of strike-slip reactivation within the contemporary stress field.

Fractures in the northern plains, stream patterns, and the midcontinent stress field

1987 ◽  
Vol 24 (6) ◽  
pp. 1086-1097 ◽  
Author(s):  
Mel R. Stauffer ◽  
Don J. Gendzwill
Keyword(s):  
Stress Field ◽  
Horizontal Stress ◽  
The Body ◽  
North American Plate ◽  
Plate Motion ◽  
Viscous Drag ◽  
Near Surface ◽  
The North ◽  
Elastic Rebound ◽  
Western North Dakota

Fractures in Late Cretaceous to Late Pleistocene sediments in Saskatchewan, eastern Montana, and western North Dakota form two vertical, orthogonal sets trending northeast–southwest and northwest–southeast. The pattern is consistent, regardless of rock type or age (except for concretionary sandstone). Both sets appear to be extensional in origin and are similar in character to joints in Alberta. Modem stream valleys also trend in the same two dominant directions and may be controlled by the underlying fractures.Elevation variations on the sub-Mannville (Early Cretaceous) unconformity form a rectilinear pattern also parallel to the fracture sets, suggesting that fracturing was initiated at least as early as Late Jurassic. It may have begun earlier, but there are insufficient data at present to extend the time of initiation.We interpret the fractures as the result of vertical uplift together with plate motion: the westward drift of North America. The northeast–southwest-directed maximum principal horizontal stress of the midcontinent stress field is generated by viscous drag effects between the North American plate and the mantle. Vertical uplift, erosion, or both together produce a horizontal tensile state in near-surface materials, and with the addition of a directed horizontal stress through plate motion, vertical tension cracks are generated parallel to that horizontal stress (northeast–southwest). Nearly instantaneous elastic rebound results in the production of second-order joints (northwest–southeast) perpendicular to the first. In this manner, the body of rock is being subjected with time to complex alternation of northeast–southwest and northwest–southeast horizontal stresses, resulting in the continuous and contemporaneous production of two perpendicular extensional joint sets.

Stress Path Analysis of the Depleted Middle Miocene Clastic Reservoirs in the Badri Field, Gulf of Suez Rift Basin, Egypt

2021 ◽  
Author(s):  
Ahmed E. Radwan ◽  
Souvik Sen
Keyword(s):  
Path Analysis ◽  
Pore Pressure ◽  
Middle Miocene ◽  
Stress Path ◽  
Horizontal Stress ◽  
Gulf Of Suez ◽  
Normal Faulting ◽  
Future Production ◽  
Uniaxial Compaction ◽  
Rate Optimization

Abstract The purpose of this study is to evaluate the reservoir geomechanics and stress path values of the depleted Miocene sandstone reservoirs of the Badri field, Gulf of Suez Basin, in order to understand the production-induced normal faulting potential in these depleted reservoirs. We interpreted the magnitudes of pore pressure (PP), vertical stress (Sv), and minimum horizontal stress (Shmin) of the syn-rift and post-rift sedimentary sequences encountered in the studied field, as well as we validated the geomechanical characteristics with subsurface measurements (i.e. leak-off test (LOT), and modular dynamic tests) (MDT). Stress path (ΔPP/ΔShmin) was modeled considering a pore pressure-horizontal stress coupling in an uniaxial compaction environment. Due to prolonged production, The Middle Miocene Hammam Faraun (HF) and Kareem reservoirs have been depleted by 950-1000 PSI and 1070-1200 PSI, respectively, with current 0.27-0.30 PSI/feet PP gradients as interpreted from initial and latest downhole measurements. Following the poroelastic approach, reduction in Shmin is assessed and reservoir stress paths values of 0.54 and 0.59 are inferred in the HF and Kareem sandstones, respectively. As a result, the current rate of depletion for both Miocene reservoirs indicates that reservoir conditions are stable in terms of production-induced normal faulting. Although future production years should be paid more attention. Accelerated depletion rate could have compelled the reservoirs stress path values to the critical level, resulting in depletion-induced reservoir instability. The operator could benefit from stress path analysis in future planning of infill well drilling and production rate optimization without causing reservoir damage or instability.

Geodynamic implications of the Cenozoic stress field on Seymour Island, West Antarctica

2008 ◽  
Vol 20 (2) ◽  
pp. 173-184 ◽  
Author(s):  
A. Maestro ◽  
J. López-Martínez ◽  
F. Bohoyo ◽  
M. Montes ◽  
F. Nozal ◽  
...  
Keyword(s):  
Stress Field ◽  
Antarctic Peninsula ◽  
Horizontal Stress ◽  
Weddell Sea ◽  
Scotia Sea ◽  
Compressional Stress ◽  
The North ◽  
Stress States ◽  
Bransfield Basin ◽  
Minimum Horizontal Stress

AbstractPalaeostress inferred from brittle mesostructures in Seymour (Marambio) Island indicates a Cenozoic to Recent origin for an extensional stress field, with only local compressional stress states. Minimum horizontal stress (σ3) orientations are scattered about two main NE–SW and NW–SE modes suggesting that two stress sources have been responsible for the dominant minimum horizontal stress directions in the north-western Weddell Sea. Extensional structures within a broad-scale compressional stress field can be linked to both the decrease in relative stress magnitudes from active margins to intraplate regions and the rifting processes that occurred in the northern Weddell Sea. Stress states with NW–SE trending σ3are compatible with back-arc extension along the eastern Antarctic Peninsula. We interpret this as due to the opening of the Larsen Basin during upper Cretaceous to Eocene and to the spreading, from Pliocene to present, of the Bransfield Basin (western Antarctic Peninsula), both due to former Phoenix Plate subduction under the Antarctic Plate. NE–SW σ3orientations could be expressions of continental fragmentation of the northern Antarctic Peninsula controlling eastwards drifting of the South Orkney microcontinent and other submerged continental blocks of the southern Scotia Sea.

Geomechanical Approach in Classification of Borehole Failures in Fractured Carbonates of Boca De Jaruco Field

2021 ◽  
Author(s):  
Anna Vladimirovna Norkina ◽  
Iaroslav Olegovich Simakov ◽  
Yuriy Anatoljevich Petrakov ◽  
Alexey Evgenjevich Sobolev ◽  
Oleg Vladimirovich Petrashov ◽  
...  
Keyword(s):  
Stress State ◽  
Horizontal Wells ◽  
Horizontal Stress ◽  
In Situ Stress ◽  
Vertical Wells ◽  
Stress Regime ◽  
Geophysical Information ◽  
The Republic ◽  
Maximum Horizontal Stress

Abstract This article is a continuation of the work on geomechanically calculations for optimizing the drilling of horizontal wells into the productive reservoir M at the Boca de Haruco field of the Republic of Cuba, presented in the article SPE-196897. As part of the work, an assessment of the stress state and direction was carried out using geological and geophysical information, an analysis of the pressure behavior during steam injections, cross-dipole acoustics, as well as oriented caliper data in vertical wells. After the completion of the first part of the work, the first horizontal wells were successfully drilled into the M formation. According to the recommendations, additional studies were carried out: core sampling and recording of micro-imager logging in the deviated sections. Presence of wellbore failures at the inclined sections allowed to use the method of inverse in-situ stress modeling based on image logs interpretation. The classification of wellbore failures by micro-imager logging: natural origin and violations of technogenic genesis is carried out. The type of breakout is defined. The result of the work was the determination of the stress state and horizontal stresses direction. In addition, the article is supplemented with the calculation of the maximum horizontal stress through the stress regime identifier factor.

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