... However, when drilling the exploration well, an over-pressured shale layer was encountered overlying the carbonate reservoir which was not anticipated. The over-pressured shale layer generated a low velocity interval that subsequently led to large depth errors compared to the prognosed depth...

... in the interpreted logs concluded that both the Izhara and Hamlah formations are hydrocarbon-bearing reservoirs. The Lower Jurassic section is comprised of sequences of shallow marine mixed carbonates intercalating with shale and anhydrite streaks. These formations, although exhibits a gradual thickening from...

..., estimation of wavelets and low frequency modeling. These help us to understand the relationship between reservoir and acoustic properties. In this study, sonic logs were acquired in highly deviated wells penetrating highly anisotropic shale formations. These logs needed corrections before integrating...

... while drilling drilling data acquisition evaluation interpretation thickness society reservoir characterization calculation permeability inversion structural inversion workflow edar inversion formula lwd resistivity extra-deep azimuthal resistivity inversion completion design shale...

... Abstract Shale ‘stability’ has been extensively studied the past few decades in an attempt to understand wellbore instability problems encountered while drilling. Drilling through shale is almost inevitable, it makes up 75 percent of sedimentary rocks. Shale tends to be characterized as having...

..., RCA, MICP, XRD were adopted into this study. Furthermore, we have also utilized 2D&3D seismic to illustrate the spatial distribution of Tuwayil siliciclastic setting and interior sediment pattern. Basically, the Tuwayil sand-shale interval represents the infilling of Mishrif/Shilaif intrashelf...

... Abstract The operational drilling history in a particularly challenging shale consistently shows that once the formation's shale reacts, and starts to disperse, in the face of a typical water base mud application, a variety of hole problems are experienced by the operator. These problems...

... requirements and complications resulting from regional politics. A High-Performance Water Based Mud (HPWBM) system was selected to address the aforementioned issues. The HPWBM was customized to respond to the subsurface conditions with the main requirement to provide maximum shale inhibition through a non...

... of products ( Fig. 6 ) compatible with the applications in carbonates and medium-hard shales. Several 4D dynamics simulations were done in different scenarios to analyze the different BHA configurations and generate a drilling parameters roadmap for each formation (and the transition between them...

.... Fig. 2 presents examples of DECT images for two selected depths used for testing from each shale formation. Failure Analysis—Strength Anisotropy Strength anisotropy was evaluated using the plane of weakness model ( Jaeger & Cook, 1979 ). The model assumes a heterogeneous media composed...

...), casing while drilling (CWD), and steering assembly were deployed to build safely in unstable shale and land at a high angle within the reservoir close to the roof in a relatively slim hydrocarbon column. The reservoir presents a succession of clinoforms. Good porosity and permeability streaks are present...

... Abstract Maintaining wellbore stability while drilling is critical to mitigate operational problems and reduce well construction costs. This is clearly evident in the case of drilling troublesome intervals such as shale formations. The current study describes the effect of diethylenetriamine...

... shales and need high mud weight to guarantee hole stability. Historically an additional casing string used in order to isolate a loss zone prior to the shale formation to drill it with high mud weight. This approach limited the inclination across shales and penetrated it along with the loss zone in same...

... geological information is shown at the transition between the sand and shale facies. Available literature ( Harilal et. al. 2004 ; Saha 2009 ; Singh et. al 2013 ) studies provide us with some sand distribution maps based on other drilled well information in the region. Also, Vp/Vs and S-Impedance...

... has been subdivided into Lower, Middle and Upper Gachsaran Members. The Lower Member is predominantly evaporitic, becoming more argillaceous carbonate and shale –bearing in the the Middle Member with comparatively less anhydrites. The Upper Member contains mainly anhydrites with interbedded shales...

... and orientation. Discussion from Drilling Perspective For the wells considered, practices employed to drill wells have been uniform with similar BHA standoffs and stiffness ratios. The drilling, hole conditioning, tripping practices and the well trajectories particularly across problematic shales were...

... Importance of shale and tight reservoirs has dramatically increased since the beginning of the century due to shale boom in the United States. Technologies such as horizontal drilling and multistage hydraulic fracturing have allowed producing oil and gas commercially from these reservoirs...

... Devonian Upstream Oil & Gas anticline sandstone intercalation basin sequence succession interpretation Ahnet Basin shale unconformity limestone maximum thickness Algeria Silty satellite survey Introduction The fully integrated modelling of subsurface seismic and well data...

... reservoir geomechanics Reservoir Characterization horizontal section drilling process Upstream Oil & Gas information vertical section drilling parameter phyllite geomechanical property shale mechanical specific energy WOB correlation MPa limestone lithology drilling data...

... by plane-parallel sand laminations intercalated by shaly levels (late stage turbidity sandstone beds - characterization by Mutti, 1992 ). The oil bearing reservoir, is producing both from thick sands and thin layer sands. It is supposed the presence of up to 40% of sand-shale inter-bedded layers...