Well Logging
Well logging services
Water quality: pH, temperature, conductivity, Redox
Water quality: pH, temperature, conductivity, Redox
Wellfield Services offers trustable Temperature, Salinity, pH, Eh and Pressure registries in water wells, using sensors that are periodically calibrated using patron solutions, verified by USA laboratories measurements.
Multifingers Caliper
Multifingers Caliper
This tool is ideal to provide high resolution details on well casing conditions at depth. Several fingers allow detecting small anomalies, easing the finding of deformations, incrustations or casing metal thinning caused by corrosion. The tool counts on 20 to 80 fingers, depending on well casing diameter.
CBL, VDL and CCL
CBL, VDL and CCL
Cement Bond Log (CBL), Variable-Density Log (VDL) and Casing Collar Locator (CCL) services offer a complete evaluation of well wall and casing to reduce the uncertainty about hydraulic isolation quality in the production zone, making possible more efficient well refining operations at a minimum cost.
Structures confirmation
Structures confirmation
Acoustic and optical televiewers records offer a precise confirmation of wells orientation with respect to geological mapping, identifying structure in cores and comparing this information with the televiewer data, discriminating faults type and shear zones allover along the well depth.
Density
Density
Well wall in-situ density continuous recording is performed with a formation-density sensor, which provides data to identify low density as well as high density stratus related, for instance, to coal presence and basic metal mineralogy, respectively.
Deviation / Wells trajectory
Deviation / Wells trajectory
The well trajectory or deviation is registered through directional tools which spatially locate each sector with respect to the well collar. These tools consist of electronic sensors which are lowered into the well using a winch.
Wellfield Services apply a plan of quality assurance consisting of tools calibration control, trajectory registries in both lowering and uprising sensor phases, pre and post well drilling checks, in conjunction with a strict control of the processing center proceedings.
Wells diameter (Caliper)
Wells diameter (Caliper)
The mechanic caliper well profiling represents the average well diameter, as detected by the tool mobile fingers that are adjusted through springs.
The caliper anomalies could represent fractures, stratification plans, fluid transmission cavities and, usually, show the distance between the fractures that cross with wells.
Downhole / Crosshole
Downhole / Crosshole
Dowhole and Crosshole are seismic techniques to measure wave’s propagation velocity in wells, with higher precision and resolution compared to surface recordings.
The Downhole registry consists in a tri-axial geophone lowered into a well while seismic waves are generated on surface. At specific depths, the geophone records directly the waves transmission times.
The Crosshole utilizes two wells, one to generate the seismic waves and the other to register the wave’s transmission times from one to the other.
Lefranc test
Lefranc test
Test to measure permeability in permeable or semi-permeable soils. The test measures the flow needed to maintain a constant water level in a well (static load) or, alternatively, the water level decay velocity (variable load).
Lugeon test
Lugeon test
Test to estimate the permeability in rocky soils, measuring the water flow that can be injected at constant pressure in different well sections.
Flowmeter, spinner
Flowmeter, spinner
A rotating instrument is utilized to measure the fluid flow inside a well. An helicoidal-shaped (blade) rotor gains a certain rotation speed which is related to the effective flow velocity.
North seeking Gyroscope
North seeking Gyroscope
This tool records the well orientation with no need for a surface azimuth reference. Knowing the tool depth and the azimuth and inclination registries, it is possible to determine the well´s North and East deviations as well as the altitude with respect to its surface well collar.
Wellfield Services performs these measurements with both single stations and continuous methods, applying a plan of quality assurance to guarantee the registry precision.
Mechanic Gyroscope
Mechanic Gyroscope
Since 1994, Wellfield Services performs mechanic gyroscope registries of wells trajectory. This technique is not affected by magnetic effects and allows high precision recording of azimuth and inclination in both open wells and inside bars.
Maxibor
Maxibor
Maxibor tools allow measuring the well deviation, functioning in memory mode without needing acquisition system and winch. It is particularly useful for the pipeline assisted ascending logs because does not require a cable and is not affected by the drill rods rotation. Anyway, it needs the azimuth as a start reference which must be measured using another tool.
Structures orientation
Structures orientation
Using the high definition acoustic and optical televiewers registries, (equivalent and complementary), Wellfield Services analyzes discontinuities and structures and evaluates the fracture index (FI).
Ascending well profiling
Ascending well profiling
Wellfield Services counts on a wide experience in positive (ascending) well logs, such as in underground mining tunnels toward the surface, which require special installation and additional well tools.
Induced Polarization IP logs
Induced Polarization IP logs
IP well profiling to investigate mineralization, especially disseminated Sulphur.
High Pressure (P) and Temperature (T) well logs
High pressure P and temperature T well logs
Wireline logs in geothermal high P and T wells with memory tools.
Neutron porosity
Neutron porosity
Porosity well log based on slowing down and capture of neutrons by the hydrogen contained in the subsoil formations. This technique allows registering the correct porosity for specific formations, (limestone, sandstone, dolomite), assuming that formation pores are fluid-filled and in units related to formation type (vol/vol or u.p.). The measurement is statistical and based on thermal neutron detection, so precisions is higher for high counting speed, i.e. low porosity.
Hydraulics test
Hydraulics test
The test consists of a pressured water injection into an isolated sounding portion, closed on one or both sides by one or two packers, to measure the amount of water that can be absorbed by the ground. It is applied on rock or consolidated ground with medium to low permeability.
Free Point / pipes rescue
Free Point / pipes rescue
The rescue of a pipe or a flexible pipe string stuck deep in a well but free to move, is based on cutting it and locating its free point in such a way to eliminate the problem down below the cut.
Gamma Ray
Gamma Ray
Gamma Ray log is used to discriminate different lithologies through their specific natural radioactivity, and for Uranium exploration. Gamma ray count increments can be related to lithological changes, alterations and radioactive mineralizations.
16 / 64 Resistivity
16 / 64 Resistivity
The Formation Resistivity well log is measured through 2 current (A and B) and 2 potential (M and N) electrodes. A and M are located on the probe, B is on the cable armature and N on the surface.
Slickline
Slickline
Wellfield uses Slickline units for services in production wells, such as memory profiling, well depth determination, well diameters calibration, pipes integrity, locating and /or recovering of production accessories (foot valves, BN, gas mandrels, blind stoppers, packers, etc.), deep and bottom sampling.
Sonic (FWS)
Sonic (FWS)
The technique for a sonic or acoustic velocity well profile uses acoustic transducers to transmit ultrasonic waves through the well fluid into the surrounding rock. This technique allows to determine in-situ compressional and shear waves to calculate the rock mechanical properties. Also, these registries can detect fractured zones and estimate permeability.
Magnetic Susceptibility
Magnetic Susceptibility
Magnetic susceptibility (MS) measurements provide a fast assessment for rock magnetic minerals content. This useful information is used for geological and hydrothermal alteration interpretations as well as to evaluate deposits with highly magnetic minerals such as some kinds of iron minerals.
High resolution acoustic Televiewer
High resolution acoustic Televiewer
Wellfield Services introduced the Borehole Televiewer technique in Chile in 1996, developing a wide experience in its application.
The high resolution acoustic Televiewer provides well wall pseudo-images to investigate the subsoil structure features through computer assisted images reconnaissance. It consists of a transductor operating at high frequency in pulse-eco mode. The important amount of obtained information, combined with a classification scheme for structural features and with the lithological, geological, chronology and tectonic information, all together, are ideal for structural statistical analysis. The technique is applicable to large scale structure, up to various meters size, as well as to microstructures.
High Temperature Acoustic Televiewer
High Temperature Acoustic Televiewer
This tool is used in high temperature geothermal wells to investigate the subsoil structural characteristics based on well wall imaging.
High resolution optical Televiewer
High resolution optical Televiewer
If the well is dry or filled with clean transparent fluid, it is possible to obtain a well wall high resolution true colors optical image. This also provides information about the fractures infilling material, besides of all the other information. The best performance is for diamond drilled smooth and even well walls, intercepting colored rocks.
Vertical seismic profile (VSP)
Vertical seismic profile (VSP)
This borehole seismic register is realized on correlation with surface seismic data to obtain higher resolution images to support interpretation. The measurements are obtained placing geophones along vertical wells and the seismic source on the nearby surface. In addition to wells and seismic data correlation, the VSP allows conversion of seismic data to cero phase data and discrimination of primary reflection from multiple reflections.