L&TD

Borehole Compensated Sonic tools determine the time required for a compressional sound wave to travel through one foot of formation. The travel time depends upon the formation's lithology, porosity, and type of pore fluid. Thus, if lithology and type of pore fluid are known, travel time can be related to porosity.

As an aid to interpretation of seismic data, the compres­sional travel times are integrated and the results indicated on the log. A tick mark appears on the log for each millisecond of elapsed time. The interval between tick marks indicates the depth interval through which sonic waves travel in 1 millisecond.

Compensated Sonic tools contain two acoustic trans­mitters and two acoustic receivers. The standard arrange­ment of these components results in travel time measure­ments made with transmitter-to-receiver spacing of 3 and 5 feet. The use of such multiple travel time measure­ments allows for compensation for borehole fluids, borehole rugosity, and tool tilt

Compensated Sonic tools are run in liquid-filled wells and should be centralized in the borehole. The tools can be combined with other tools such as Gamma Ray, Induction, Laterolog, Density, Neutron, and Caliper.

•  Porosity analysis

•  Lithology identification

•  Abnormal pressure identification

•  Velocity data for seismic studies

INTRODUCTION

In surface readout production logging the production logging tools are run on conducting wireline which is run from surface through a pressure control system (usually grease injection). Power is sent down the line and data from the production logging tools is relayed up via a telemetry system and decoded. This data is merged with depth and line speed data from the wireline unit’s measuring head and the logging data is displayed real time.

Benefits and Features:

•  Perforation in highly deviated or horizontal wells
•  Very safe since the well can not blow when perforating
•  The needed for perforration is very little
  
•  Perforate can be under or over balanced for many formations with hundreds meters of perforated interval.
  
•  Perforation under balanced gives deep penetration stable antry holes.

Specifications 

•  Gun O.D.: 3-3/8”
•  Casing O.D: 4.5”
•  Shot Density (spf): 6
•  Gun type: Scalloped gun systems
•  Entry hole: 0.59” (Concrete target)
•  Concrete target penetration: 31.12” (Concrete target)

Time Vs Temperature chart for explosives

The picture shows the result of production logging after perforation using TCP

Perforation intervals:

4271 - 4282,

4285 - 4291,

4294 - 4314 m.

versus producing flows at: 24.3, 17.1 and 3.6 m3 of oil per day.

          The program has two basic options to evaluate these parameters:

·    The general case when any type of hydrocarbons may be present and hence the density of hydrocarbons is not known.

·    When density of hydrocarbons is known and there is little or no invasion. This option is primarily designed to evaluate tight gas sands where the density of gas is usually known and there is no invasion due to very low permeability.

Shale content is computed from one or several (as a minimum) of the following shale indicators: Gamma Ray, SP, Deep resistivity curve, Thorium, Potassium, Thorium+Potasium, Neutron, Density-Neutron cross plot, and Density-Acoustic cross plot; or an external shale volume Vsh is used for the volume of shale.  

Porosity is computed from the Density-Neutron cross plot or Density-Acoustic cross plot or single porosity logs: Density, Neutron or Acoustic. Salt and coal can be identified when necessary by setting flags and cut-off values. SASHA also corrects for the excavation effect (if desired).

Permeability can be computed from one of two equations: Timur or Wyllie-Rose. Effective permeabilities for hydrocarbons and water are also computed

Fig. 1 – Results of SASHA processing for Shaly Sand

Features: 

  - Toolpusher is a tool transport system use to convey the logging tools to the bottom of the well, when e-line can not get the tools to T.D.

- In many instances experience has proven that much less rig time is used, if Toolpusher is utilized first. 

-  Depending on depth, Toolpusher operations consume about 3 to 4 time more time than e-line conveyed operations.

- Any e-line service can be provided via Toolpusher.

DSN II is a superior neutron porosity tool. This is due to detector array optimization. Far detector count rates are much greater than ever before. Other advantages stem from the ratio-porosity relationship. Detailed analysis shows that DSN II statistical uncertainty has been significantly reduced compared with previous top-performing tools, while the overall signal-to-noise ratio is notably better than before.

Tool specification

These features translate into porosity measurements with outstanding  precision. DSN II delivers porosity measurements with greater accuracy and repeatability than any other neutron porosity service. Designed for use in liquid-filled holes, both open and cased, this service provides:

• Superior accuracy. Consistent measurements over the entire porosity range, even in cased holes.

• Repeatable results. Optimized detector spacing, advanced calibration methods and greater count rates contribute to the service’s outstanding precision.

• Improved thin bed evaluation. Clearer delineation of thin bed formations with Enhanced Vertical Resolution (EVR), available real time or in post processing.

• Increased reservoir understanding. A combination of logging tools can be run to identify lithology, reveal gas zones and calculate shale volumes

• Faster log runs. Save rig time with an optimized design that enables logs to be run at faster cable speeds

• Gas detection. Excellent indication of gas when used in combination with a density log

• Dykes detection. Excellent Effect of basement’s dyke identification when used in combination with a density log

       CORAL Analysis provides an accurate detailed description of reservoirs and mixed lithology. Its primary use is in the evaluation of formations, which contain shale, sand, limestone, dolomite, anhydrite, and gypsum. Minimum log data consists of a gamma ray or spontaneous potential log; a density, neutron, or sonic porosity log; and an induction or laterolog resistivity log. Improved results are obtained if photoelectric (Pe), shallow resistivity, sonic, dielectric, and spectral gamma ray data are used.    

        These logs will provide determination of shale content, cross plot lithology (sandstone-limestone or limestone-dolomite), anhydrite content, porosity, secondary porosity or gypsum (if an acoustic log is available), permeability and water saturation. If it is known that there is no limestone in a formation, the combination of sandstone-dolomite can be evaluated.
        Shale content can be computed from a number of shale indicators: Gamma Ray, SP, Deep resistivity curve, Thorium, Potassium, Gamma ray Thorium+Potasium, Neutron, Alternative Indicator, External Shale Volume, Density-Neutron cross plot, and Density-Acoustic cross plot. Several of these shale indicators can be used simultaneously, and then the minimum shale content of several shale volumes will be computed.
        Matrix densities of major minerals (sand, lime, dolomite, and anhydrite) can be changed within certain limits if necessary when solving density-neutron cross plot for lithology and porosity. Correction for gas can be done if density of gas is known. Salt and coal contents can be identified by setting the appropriate flags. There are options to compute porosity from single porosity logs (Density, Neutron or Acoustic) Several equations are included to compute water saturation: Archie. Simandoux, Indonesia, Waxman-Smits, and Dielectric analysis models.   Permeability can be computed from one of two equations: Timur or Wyllie-Rose. Effective permeabilities for hydrocarbons and water can be computed from one of the three equations: Park Jones, Boatman, or Pirson.

This program has been used popularly in L&TD for sedimentary rock evaluation.

Tool response equations available are SP, GR, Rt, Rxo, density, neutron and sonic.

Figure 1 shows the result of a CORAL processing for Shaly Sand-Lime-Dolomite with coal. The unknowns are porosity, clay volume, sand volume, water saturation, water saturation in flushed zone, hydrocarbon density, lime volume, dolomite volume, coal volume, and permeability index.

Fig. 1 – Results of CORAL processing for Shaly Sand-Lime-Dolomite with Coal

Nhóm Marketing

 K10 “Quazrtz”

The K10 “Quartz” is a slick line, E-line , or coiled tubing conveyed downhole memory gauge with significantly enhanced capabilities. In the basic configuration it is a low-cost, hight realiability pressure and temperature recorder. With enhanced feature, it is a low-cost, instrument producing pressure, temperature, and flor along with depth data for a more complete well survey.

 Features

• Entire designed, manufactured and assembled in U.S.A.

• “Quartzdyne” quartz resonator transducer

• Battery management system within sofware

• Buit-in Surface Readout (SRO) mode

• Delta P/Delta T sampling options

• Redundant memory

• Low power requirement

• USB interface for fast downloading

• Depth data with sireal encoder for Pressure/Time vs. Depth/Time

• Upgradeable Firmware

• Optional Flowmeter

 Application

• Static and flowing gradient tests

• Downhole leak detection

• Detecting flowing zones

• Injection testing

• Gas lifting optimization

• Drillstem testing

IV. DATA INTERPRETATION

At present, VSP well testing team uses Ecrin sofware includes modules for Pressure Transient Analysis (Saphir) and Production Analysis (Topaze).. This software can calculate reservoir parameters as Pi - initial pressure, K - permeability, C - well bore storage, S - skin, R - effect radius, Kh – Perm thickness product, etc. with high accuracy and reliability. It can interpret testing data on oil, gas, water well with different geologic models. 

Spectral Density Log provides superior formation bulk density (r_b) and borehole Compensated photoelectric factor (Pe) measurements. These measurements are key factors for

• Accurate determination of formation bulk density
• Reliable identification of formation lithology, regardless of formation fluid type
• Precise delineation of thinly bedded formations (the unfiltered Pe curve is used)
• Excellent indication of gas when used in combination with a neutron log
• Excellent effect of basement dyke identification when used in combination with a neutron  log