The bound fluid volume (BFV) measured by CMR overlaid irreducible water measured by the magnetic resonance while drilling tool, demonstrating that, under comparable conditions, the two measurements are closely interchangeable and will lead to consistent results.Īfter proving data overlay in the water zone, the same measurement was observed in the oil zone. In the water zone, the LWD NMR and combinable magnetic resonance (CMR) data were directly comparable and equivalent. The cylindrical symmetry allows the collar to rotate freely without affecting the measurement. The magnetic field has a low gradient, minimizing diffusion effect. collar centered in the borehole using two spiral stabilizers, performed a focused measurement over a resonating ring zone 14 in.
Well log edition techlog plus#
The pilot well also provided an opportunity to validate the new NMR measurement available in Schlumberger’s proVISION Plus magnetic resonance while drilling tool. The zone indicated by the green rectangle was dolomitized with the predominant texture consisting of macro-pores.ĭifferences in textures indicate effective permeability in the second layer up to 10 times larger than the top interval of similar porosity, leading to a decision to bypass the top layer in the horizontal section. The area in the orange box is a layer of predominant calcite lithology and meso-pores texture. In Figure 1, the two boxed sections show the top two potential target layers. The deployment of the LWD tool was a first for the operator, who used synthetic oil-base mud (SOBM) in the pilot well. NMR tools were chosen to analyze the rock texture and determine the connectivity of the pore structure. Lithology was defined in the pilot well using capture spectroscopy by a pulsed neutron LWD source, coupled with high-resolution NaI detectors. The challenge was to understand the multi-mineral composition of the rock and identify intervals with the largest production potential. An optimized physical transmission rate was selected to obtain real-time data similar to memory data. The bottomhole assembly (BHA) in the pilot well consisted of a PDC bit, point-the-bit rotary steerable tool, LWD laterolog imager, LWD nuclear magnetic resonance (NMR) tool, LWD multifunction formation evaluation tool and measurement-while-drilling (MWD) tool to transmit real-time data. The team utilized Schlumberger’s logging-while-drilling (LWD) and wireline technologies to compare the two, characterize log reservoir signatures before and after mud filtrate invasion, and support real-time horizontal well petrophysics interpretation for geosteering decisions in the subsequent well. The S-shape pilot well crossed stratigraphically the whole reservoir, with the team from OGX Petróleo e Gas and Schlumberger using data to identify a target zone for a 1,000-meter lateral in the horizontal well. It is superimposed over the black curve, which is the input.
In the circled portion of the graph, the blue curve is the output of the Techlog K.mod module.
Well log edition techlog for free#
Cores and electric/ultrasonic image logs in the pilot well identified closed and oil-bearing open fractures.įigure 2 shows the neural network results for free fluid volume. The average porosity is 15%, occasionally reaching 25%. The upper segment includes mostly beds of grain-supported limestone with secondary siliciclastic richer beds. The complex reservoir section consists of a lower half dolomitized with metric thickness shoaling upward cycles from matrix to grain-supported rocks.
Operator OGX Petróleo e Gas faced the task of identifying target zones in an Albian (Upper Cretaceous) carbonate reservoir. Net pay was 80%, exceeding the initial goal of 65%. The combination of technological innovation and groundbreaking methodology has enabled the industry to evaluate complex carbonates and achieve higher-than-expected net pays in the Quissamã Member of the Macaé Formation.įollowing a pilot well, the first completed horizontal well resulted in an estimated maximum achievable flow rate of 40,000 bbl/day of oil without movable water. The green area was dolomitized with the predominant texture consisting of macro-pores. The orange area is a layer of predominant calcite lithology and meso-pores texture.
The boxed areas of this composite plot for the well show the top two potential target layers. Figure 1: One challenge of a pilot well offshore Brazil was to understand the multi-mineral composition of the rock and identify intervals with the largest production potential.