Pore pressure variation within the Tuscaloosa trend: Morganza and Moore-Sams Fields, Louisiana Gulf Coast

1992 ◽  
Vol 97 (B5) ◽  
pp. 7193 ◽  
Author(s):  
Suzanne D. Weedman ◽  
Albert L. Guber ◽  
Terry Engelder
SPE Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Weicheng Zhang ◽  
Andreas Eckert ◽  
Steven Hilgedick ◽  
Harvey Goodman ◽  
Meng Meng

Summary Understanding the cement hardening process and determining the development of the state of stress in the cement under specific downhole conditions are challenging but fundamental requirements to perform an accurate prediction of wellbore integrity. As an essential component of the state of stress, the temporal variation of cement pore pressure is a critical factor that affects the occurrence of cement failure. In this study, we present a novel laboratory setup to measure the cement pore pressure variation during hardening under representative downhole conditions, including the pressure, temperature, and water exchange between the cement and formation. The pore pressure measurements are further incorporated with a staged finite element analysis (FEA) approach to investigate the state of stress development during cement hardening and to evaluate cement failure under different operations and after different wait-on-cement (WOC) periods. The laboratory measurements show that the external water supply from the formation significantly impedes the pore pressure drop in the cement. The numerical results indicate that the accelerated pore pressure decrease obtained without considering downhole conditions elevates the contact pressure at the cement-formation interfaces significantly and moderately increases the von Mises stress in the cement. The numerical results further predict that the accelerated pore pressure decrease leads to an overestimation of shear failure during pressure testing and steamflooding operations but an underestimation of debonding failure during severe fluid loss and injection-related cooling processes. Based on the results of the integrated laboratory and numerical approach, qualitative and quantitative suggestions are provided for field operations to inhibit wellbore integrity risk during the wellbore life cycle.


2018 ◽  
Vol 9 (3) ◽  
pp. 2065-2079 ◽  
Author(s):  
Caspar Daniel Adenutsi ◽  
Zhiping Li ◽  
Fengpeng Lai ◽  
Anthony Edem Hama ◽  
Wilberforce Nkrumah Aggrey

Author(s):  
Sung-Ho Song ◽  
Gyu-Sang Lee ◽  
Jin-Sung Kim ◽  
Jong-Hak Choi ◽  
In-Ky Cho

2012 ◽  
Vol 577 ◽  
pp. 163-166
Author(s):  
Yu Wei Li ◽  
Jia Liu ◽  
Chao Yang Hu ◽  
Shuang Li ◽  
Yu Liu

Considering pore pressure variation of sidewall rock, which is caused by drilling fluid filtering, the porosity variation model of sidewall rock in sandstone reservoir and effective stress factor variation model are established, and according to relationship between pore pressure and total volume strain of sandstone, the calculation model of safe window of drilling fluid density on sandstone reservoir, with which considered variation of porosity and effective stress factor are finally established. Applying the calculation of this model shows that: with increased function of drilling fluid filtering, which is as increased as pore pressure of sidewall rock, caving pressure that ensures well hole stability is increased, fracturing pressure is decreased, safe window of drilling fluid is narrowing, and that is against of safety drilling.


Author(s):  
Marieh Rajaie ◽  
Amir H. Azimi ◽  
Ioan Nistor ◽  
Colin D. Rennie

Pore pressure and scour formation around coastal structures have been investigated in the past which led to a relationship between the hydrodynamics of tsunami waves and sediment erosion around coastal structures. With the objective of developing a comprehensive model to assess the interaction of hydrodynamic conditions, induced scour, soil pore pressure, and beach slopes, this novel study aims to examine (1) the effect of hydrodynamic forcing factors such as bore depth on scour and pore pressure generation on both horizontal and inclined bed conditions and (2) the effect of bed slope on the scour and pore pressure development and (3) the influence of the soil pore pressure on scour around a square shaped structure.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/dTQ-_GLhtzs


1984 ◽  
Vol 21 (3) ◽  
pp. 439-448 ◽  
Author(s):  
J. C. Sobkowicz ◽  
N. R. Morgenstern

Gassy soils are defined as those soils which contain a relatively large amount of gas dissolved in the pore fluid. Examples include the Alberta Oil Sands, marine sediments from deep ocean locations, geopressure reservoirs along the Gulf Coast, and other naturally occurring, gas-charged reservoirs.The equilibrium behaviour during unloading with undrained boundary conditions is examined. Contrary to conventional experience with soils containing only a small amount of gas, gassy soils exhibit an equilibrium pore pressure response close to zero. Effective stress, and hence strength, decrease commensurately with total stress at the soil boundary.Laboratory observations of gassy soil behaviour are presented, which confirm the predictive accuracy of the theoretical model. Parameters important to the determination of gassy soil behaviour include the in situ state of stress (σ0 and u0), the liquid/gas saturation pressure (ul/g), the gas solubility (H), saturation (S), and the soil and liquid compressibilities (βT and βL). Key words: undrained, pore pressure, compressibility, gas, shear strength, unloading, laboratory, ex-solution.


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