Enriching the Static Earth Model through a Near-wellbore Structural Modeling Workflow Combining all Horizontal Well Data

2013 ◽  
Author(s):  
C. Dupuis ◽  
J.M. Denichou ◽  
F. Antonsen ◽  
M. Constable ◽  
P. Marza ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Structural Modeling ◽  
Earth Model ◽  
Well Data

scholarly journals Shale Reservoir 3D Structural Modeling Using Horizontal Well Data: Main Issues and an Improved Method

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhiguo Shu ◽  
Guochang Wang ◽  
Yang Luo ◽  
Chao Wang ◽  
Yalin Chen ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Structural Modeling ◽  
Shale Oil ◽  
Improved Method ◽  
Vertical Wells ◽  
3D Structural Modeling ◽  
Shale Reservoirs ◽  
Well Data

Shale oil and gas fields usually contain many horizontal wells. The key of 3D structural modeling for shale reservoirs is to effectively utilize all structure-associated data (e.g., formation tops) in these horizontal wells. The inclination angle of horizontal wells is usually large, especially in the lateral section. As a result, formation tops in a horizontal well are located at the distinct lateral positions, while formation tops in a vertical well are usually stacked in the same or similar lateral position. It becomes very challenging to estimate shale layer thickness and structural map of multiple formation surfaces using formation tops in horizontal wells. Meanwhile, the large inclination angle of horizontal wells indicates a complicated spatial relation with shale formation surfaces. The 3D structural modeling using horizontal well data is much more difficult than that using vertical well data. To overcome these new challenges in 3D structural modeling using horizontal well data, we developed a method for 3D structural modeling using horizontal well data. The main process included 1) adding pseudo vertical wells at formation tops to convert the uncoupled formation tops to coupled formation tops as in vertical wells, 2) estimating shale thickness by balancing the shale thickness and dip angle change of a key surface, and 3) detecting horizontal well segments landing in the wrong formations and adding pseudo vertical wells to fix them. We used our improved method to successfully construct two structural models of Longmaxi–Wufeng shale reservoirs at a well pad scale and a shale oil/gas field scale. Our research demonstrated that 3D structural modeling could be improved by maximizing the utilization of horizontal well data, thus optimizing the quality of the structural model of shale reservoirs.

Optimum well trajectory design in a planned well in Blacktip field, Australia: a case study

2010 ◽  
Vol 50 (1) ◽  
pp. 535 ◽  
Author(s):  
Vamegh Rasouli ◽  
Zachariah Pallikathekathil ◽  
Elike Mawuli
Keyword(s):  
Strength Properties ◽  
Earth Model ◽  
Trajectory Design ◽  
Lower Section ◽  
Principal Stresses ◽  
Stress Anisotropy ◽  
Major Fault ◽  
Well Trajectory ◽  
Mechanical Earth Model ◽  
Well Data

A geomechanics study carried out in the Blacktip field, offshore Australia led to optimum wellbore deviation and azimuth to minimise drilling-associated instability problems near a major fault in the field. Elastic and strength properties of the formations and magnitude of principal stresses in the field were estimated from a mechanical earth model (MEM) based on offset well data. The direction of the minimum horizontal stresses was predicted from formation microresistivity image (FMI) logs available in offset wells. The MEM results were calibrated using results from laboratory experiments, well tests and drilling incidents from drilling reports. The MEM showed that formations at the lower section of the well are very competent and have high uniaxial strength; however, most of the failures in the form of breakouts observed from calliper and image logs were in this interval. Therefore, obtaining a good match between the model and observed failures required a large stress anisotropy to be considered for the lower section of the wellbore. Further investigations demonstrated that this is because the wellbore trajectory at deeper depth gets closer to the major fault plane, and this large stress anisotropy is due to the stress redistribution near the fault. The data from offset well was mapped into the planned trajectory, and the selection of the optimum trajectory and a stable mud weight window for the appropriate section led to successful drilling of the deviated well.

Real-Time 3D Earth Model Updating While Drilling a Horizontal Well

2002 ◽  
Author(s):  
Alberto Malinverno ◽  
Ballard Andrews ◽  
Nicholas Bennett ◽  
Ian Bryant ◽  
Michael Prange ◽  
...  
Keyword(s):  
Real Time ◽  
Horizontal Well ◽  
Model Updating ◽  
Earth Model

Integrated study of a fractured granitic basement reservoir with connectivity analysis and identification of sweet spots: Cauvery Basin, India

2019 ◽  
Vol 38 (4) ◽  
pp. 254-261
Author(s):  
Deepa ◽  
J. Nagaraju ◽  
Binod Chetia ◽  
Rajeev Tandon ◽  
P. K. Chaudhuary ◽  
...  
Keyword(s):  
Fracture Network ◽  
Earth Model ◽  
Connectivity Analysis ◽  
Fracture Permeability ◽  
Cauvery Basin ◽  
Well Production ◽  
Fracture Intensity ◽  
Mechanical Earth Model ◽  
Well Data ◽  
Sweet Spots

Basement exploration in India has seen increased interest after the recent discovery of a field in the Cauvery Basin in southeastern India, with an average individual well production of 700 b/d from a fractured basement reservoir. The field is presently under development, with several development well locations identified for drilling. Optimized development of a fractured basement reservoir requires identification of areas with a permeable fracture network. To meet this objective, we adopted a comprehensive integrated workflow involving the use of common reflection angle migrated seismic data, fracture modeling, a 1D mechanical earth model (MEM), identification of critically stressed fractures in 3D space, fracture permeability/connectivity analysis, and sweet spot identification. The workflow yielded a robust discrete fracture network model based on 3D directional fracture intensity, a 1D MEM that gave regional stress gradients (pore pressure, overburden, Shmin, and SHmax), and rock strength and elastic properties. In addition, we generated a critically stressed 3D fracture model and performed sequential stratal surface restoration for predictive strain modeling that was calibrated at wells. Our fracture permeability and connectivity analysis showed that existing hydrocarbon-producing wells are located within areas that have a fracture cluster/swarm with associated good fracture connectivity. A 3D basement facies model constructed by integrating well data and a poststack inversion impedance volume showed that major flow zones occur in weathered basement associated with low impedance. This model, in combination with fracture intensity data, provides good indication of the location of basement sweet spots in the Cauvery Basin. The understanding gained on the controls of occurrence of basement fractures explains why some wells in the field are producers and others are dry. This led to greater confidence in optimizing the locations of previously proposed new development wells.

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