L&TD

            In memory production logging the production logging tools are run on non conducting wireline (slickline) or on coiled tubing. Power is supplied by a lithium battery at the top of the string. Instead of data being sent up the line the telemetry is decoded and data is stored in a memory tool according to a pre-programmed sample rate. Simultaneously depth and line speed data is recorded at surface in memory. After the tools are recovered from the well the two sets of data are merged with output files in ASCII format of depth, line speed and tool responses. These ASCII files are read into log plotting software and after depth correlating plotted as production logs.

L & TD has used this equipment since 1988 in hundreds wells. These wells were located at Bach Ho, Dai Hung and Rong oil fields. The angle of wells may have been to 70 degrees and the depth up to 5000 m.

This equipment can be uesd without cutting off electric supply.

Wireline perforation has been used very safely in our oil field’s. Advantages of wireline perforation is the gun can not fire if hydrostatic pressure less 10 atm and the length of the gun may be from 3 to 8 meters.

The picture shows, the well after perforation using a wireline gun.

- Density: 20 charges per meter.

- Gun size: 3-3/8”.

- Perforation intervals: 3640-3660, 3690- 3695 and 3715-3725m

This picture shows the result of production logs after perforation using a wireline gun for a production well in basement

- Shot density: 20 charges per meter.

- Gun size: 3-3/8”.

- Perforation intervals: 3680 - 3719.5 m.

FULL WAVE SONIC tool measures compressional wave, shear wave and stoneley wave in a waveform.

*FullWave module. Using a fullwave module we can present and analyze fullwave acoustic data. The program allows displaying the logged data graphically in many ways. The data images can be enhanced to emphasize certain features.

The following analysis techniques are available with FullWave:

•  Frequency Display
•  Receivers Display
•  Delta-T for IRD
•  Stoneley Delta-T
•  Stoneley Reflector
•  LWD Delta-T, LWD Delta-T Lite, or LWD Delta-T Mark II

Beside that, FullWave module allows the use of Kaiser and Finite Impulse frequency filters and from that we can see and analyze compressional wave, shear wave or stoneley wave independently.

*RockXpertTM Analysis module. Critical Information for Fracture Designs and Well Plans

• Provides valuable input to fracture-design programs that predict fracture geometry and that help select fracturing fluids, proppants, and pumping schedules.
• Determines the mud weights required to prevent sanding and fracturing during drilling.
• Provides optimal direction in which to drill deviated, horizontal, and extended-reach wells to maximize borehole stability and increase the effectiveness of subsequent hydraulic fracturing
• Provides optimal direction in which to drill deviated, horizontal, and extended-reach wells to maximize borehole stability and increase the effectiveness of subsequent hydraulic fracturing
• Assists in evaluating a well’s sanding potential to determine whether a gravel pack or frac pack may be necessary to help maintain production at optimal levels

The declination of a horizontal wellbore with respect to the principal horizontal stress can have a significant effect on wellbore stability and fracture geometry. RockXpert logs can aid in well planning to minimize borehole instability and to maximize the effectiveness of fracturing operations.

At any specified point along a proposed or existing well path, RockXpert analysis can identify stable borehole conditions as a function of mud weight and borehole deviation.

RockXpert logs indicate the safe mud-weight range to provide sanding and formation breakdown, as shown in Track 2. The logs also include gamma and caliper curves in Track 1, predicted maximum borehole deviation in Track 3, and lithology information in Track 4.

STRES, FRACHT, FRACPAR, FWSIWC modules allow us to estimate:

•  Poisson’s ratio, Young’s module, bulk module, travel time ratio
• Max compressional phase, max shear phase, max Stoneley phase, max compressional frequency, max shear frequency, max Stoneley frequency.
• Transit time at: max compressional transmissivity, max shear transmissivity and max Stoneley transmissivity
• Fracture initial pressure, fracture closure pressure

This plot shows potential zones in White Tiger fractured basement by means of the energy loss of Stoneley wave (Track 5), in fact, these zones are highly productive

Main Features:

• Up to 16 analogue   channels

• 512 Kb digital interface

• 24bit Delta-Sigma  convertors

• Built in firing circuit

• Full instrument tests

• USP interface

• Use standard PC running VSProwess software

Specifications

Analogue section

Digital section

General

Functionality

Communication with the PC recording system  is by USB serial interface. The USB interface will allow the panel to be used with all modern PC’s.

The GSP incorporates a single airgun firing circuit for use on simple checkshot surveys. For independent external control circuits give control over external source controllers such as our own RSS four gun remote gun firing system

The GSP-1 in use with a Dual analogue system

          Fig1: Acquisition Observer Log

          Fig2: Stack plot of vertical and horizontal components.

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.