geovision Resistivity imaging for productive drilling

Transcription

1 geovision Resistivity imaging for productive drilling

2 geovision Resistivity imaging while drilling helps position wells in the best place in the reservoir in less time. Real-time resistivity measurements from the geovision* imagingwhile-drilling service make drilling more productive by saving rig time and reducing costs. The high resolution of geovision images reveals formation structure and geological features, allowing wells to be steered to the best place in the reservoir to enhance production and ROI. Multiple depths of investigation permit detailed geological analysis to pinpoint reserves and optimize completion designs and stimulation strategies. Welcome to productive drilling*. FLEXIBLE BHA CONFIGURATIONS Resistivity measurements from the geovision imaging-while-drilling service can detect and image thin-bed resistivities in conductive BENEFITS Cuts costs by providing key inputs for optimizing completion design and stimulation strategy Identifies thin bed pay zones in conductive mud environments Facilitates putting horizontal wells in the best place within a reservoir by showing wellbore location relative to structure Saves rig time by acquiring data while drilling Provides accurate resistivity measurements in high-resistivity formations

3 mud environments. This information provides the detailed geological analysis required for geosteering precision in wellbores as small as in. The geovision downhole tool can be configured to make up to five resistivity measurements. Three azimuthally focused 1-in button electrodes, spaced longitudinally along the axis of the tool, provide multiple depths of investigation that permit quantification of invasion profiles. An integral, cylindrical electrode delivers a high-resolution, lateral resistivity referred to as ring resistivity. A bit resistivity measurement allows real-time coring and casing point selection in both conductive and resistive mud environments. Placement of the geovision tool in a BHA can be directly above the bit, near the bit, or above other components allowing broad flexibility in BHA configuration. In addition to five resistivity measurements, the geovision tool acquires azimuthal gamma ray data, torsional and lateral shock records, and temperature measurements. REAL-TIME IMAGING AND DIP CALCULATION FOR ENHANCED WELL PLACEMENT The azimuthally acquired electrode measurements are displayed as fullbore images in real time to graphically describe formation resistivity. Advanced built-in processing allows structural dip to be calculated downhole and transmitted to the surface in real time. This provides information about formation structure and other geological features, which aids precise placement of a wellbore within a reservoir. All data acquired are stored in memory and can be sent to the surface in real time or downloaded when the tool is returned to the surface. Advanced processing and interpretation can be done at the computing center by the same analyst who interprets FMI* Fullbore Formation MicroImager images. Gamma Ray 0 (gapi) 150 ROP (ft/h) -5 (º) 95 Events Gamma Ray 0 (gapi) 150 ROP (ft/h) -5 (º) 95 Events Static geovision Image MD 1 : 60 Dynamic geovision Image Dynamic FMI Image MD 1 : 20 Static geovision Image Dynamic geovision Image Dynamic FMI Image Bed boundary Concretion Concretion fractures Longitudinal induced conductive fracture fracture (natural) Concretions Partially healed fracture fracture (healed) The consistency of these geovision and FMI images, acquired over the same intervals in Barnett shale, demonstrates the ability of geovision imaging while drilling to provide the resistivity measurements required for detailed geological analysis. Put wells in the best place with high-resolution multidepth geovision resistivity measurements.

4 Reach TD in less time with productive drilling ACQUISITION OF HIGH-RESOLUTION BOREHOLE IMAGES WHILE DRILLING SAVES RIG TIME AND REDUCES COSTS The high-resolution borehole images provided by the geovision service facilitate detailed geological and geomechanical analyses in conductive mud environments. By providing the measurements required to identify natural fractures contributing to well productivity and both the natural and induced fractures necessary to understand the orientation of formation stresses around the borehole geovision imaging delivers key information for devising successful completion strategies. Because geovision resistivity imaging can be combined with other services, the need for an additional logging run can be eliminated, resulting in rig time savings and reduced drilling costs. RESISTIVITY IMAGING-WHILEDRILLING IDENTIFIES FRACTURES IN BARNETT SHALE In an 81 2-in well drilled in the Texas Barnett shale, geovision borehole images were used to successfully identify faults, open and healed fractures, structural and stratigraphic dip magnitudes and directions, and minimum and maximum stress orientations. A drillpipe-conveyed FMI imager was also run in the horizontal section of this well for comparison. The consistency in interpretation of the FMI and geovision images provided the validation and confidence necessary to run geovision services in future Barnett shale wells. Quality images provided by the geovision service can help pinpoint reserves in the diverse shale gas plays found in the continental United States. Niobrara Gammon Bakken Excello/Mulky New Albany Antrim Green River Cane Creek Monterey Devonian/Ohio McClure Floyd and Conasauga Lewis and Mancos Palo Duro Barnett and Woodford Caney and Woodford Woodford Barnett Fayetteville

5 Resistivity imaging-while-drilling service geovision Resistivity Specifications General Specifications geovision675* system geovision825* system Collar dimensions Nominal diameter 6.75 in 8.25 in Maximum diameter 7.75 in 9.5 in Upper head connection 5 1 /2 FH box 6 5 /8 in FH box Lower head connection 4 1 /2 Reg pin 6 5 /8 in Reg box Operating temperature Standard configuration 300 degf [150 degc] 300 degf [150 degc] High-temperature configuration N/A N/A Tool length and weight Length ft [3.08 m] ft [3.88 m] Weight 1,200 lbm [544.3 kg] 2,400 lbm [1,088.6 kg] Mechanical Specifications Dogleg severity Rotary mode 8 /100 ft 7 /100 ft Sliding mode 16 /100 ft 13 /100 ft Bending strength ratio (BSR) Upper connection BSR Lower connection BSR Equivalent bending stiffness 10 ft of ft of Average inertia 84 in in 4 Axial and rotational load Maximum weight on bit 71,000,000/L lbf 164,000,000/L lbf Maximum jarring load 330,000 lbf 640,000 lbf Maximum rotary torque 16,000 ft.lbf 23,000 ft.lbf Hydraulics Maximum external pressure 18,000 psi 15,000 psi Standard flow range 0 to 800 galus/min 0 to 1,200 galus/min Pressure drop constant (C) 135, ,000 Measurement Performance Resistivity Bit and ring Azimuthal button electrode Range 0.2 to 20,000 ohm.m 0.2 to 20,000 ohm.m Accuracy 0.1 to 250 ohm.m ± 5% ± 5% 250 to 500 ohm.m ± 10% ± 10% 500 to 5,000 ohm.m ± 20% ± 20% Noise floor 0.2 ms 0.2 ms Resistivity response Bit Ring Deep Medium Shallow Vertical resolution 12 to 24 in 2 to 3 in 2 to 3 in 2 to 3 in 2 to 3 in Depth of investigation 12 in 7 in 5 in 3 in 1 in Resistivity environments Water-base mud Because geovision resistivity is a laterolog measurement, the geovision tool should be run under conditions where R xo is less than or approximately equal to R t to ensure that the tool is sensitive to R t when there is significant invasion. Oil-base mud Correlation with bit resistivity only Gamma ray Range 0 to 250 gapi Accuracy ± 7% Statistical resolution ± 3 gapi at 100 gapi and 100 ft/h Vertical resolution 1.5 in L is the distance in ft between the stabilizer above the tool and the stabilizer below it. APPLICATIONS Real-time image and dip calculation to help position wells in the best place in the reservoir Real-time geostopping for coring and casing point selection in both oil- and water-base muds High-resolution imaging for fracture identification and complex interpretations Invasion profile analysis Thin bed analysis FEATURES Three azimuthally focused electrode resistivity measurements High-resolution focused ring resistivity At-the-bit resistivity Azimuthal gamma ray High-resolution multidepth resistivity image with full coverage Enhanced resolution image processing Combinable with all other Schlumberger drilling and measurement services Runnable directly above the bit for enhanced geosteering Resistivity measurements to 20,000 ohm.m

6 geovision Resistivity imaging provides multiple depths of investigation for productive drilling. *Mark of Schlumberger Copyright 2007 Schlumberger. All rights reserved. 07-DR-122