Well Testing

WELL TESTING SERVICES

DEFINITIONS

  • Measurement, under controlled conditions, of all parameters relating to the production of oil, gas and water from a well to provide complete and accurate data of the reservoir performance;
  • Measurement of hydrocarbons production parameters in a specific period of time, to analyse the output signal of a well when an input signal has been applied.

GOALS
Obtain information about:

  • nature and the amount of the fluids produced
  • reservoir pressure and temperature
  • characteristics of the fluids producing formation
  • efficiency of the completion
  • efficiency of the stimulation performed in the well
  • reservoir geometry
  • well drainage radius
  • interference or correlation of producing layers among wells
  • drive mechanism in the reservoir
  • production capacity
  • formation damage
  • Productivity Index for oil wells
  • Open Flow for gas wells
  • …….. and much more

OUR MAIN SERVICES ONSHORE AND OFFSHORE

Well clean-up
It is the preliminary flow operation before the well production test. The purpose of purging is to clean the well, that is to let out, through the flow, all the fluids and foreign solids that are in the well at the end of the completion:

  • Displacement fluid;
  • Completion fluid and/or some packer fluid under the packer;
  • Frac fluids, spent acid or other special cushions subsequent to a stimulation;
  • Solid debris, if the productive interval is opened by guns.

Well Testing
Production Test can be conducted on an oil&gas well and can be differentiated according to:

  • Test performance point;
  • Produced fluids;
  • Test technique;
  • Purpose.

The main production tests carried out from the drilling phase and during the producing life are:

         a. Drill Stem Test (DST)

In exploration wells, when drilling, or after the well is completely drilled, it’s possible to carry out with a temporary test string a preliminary test called “Drill Stem Test”.
These tests are very short and use Bottom Hole Assembly which allows the string to be close an open at bottom hole.
The objectives of a Drill Stem Test are to determine the following main parameters:

  • Initial reservoir pressure and temperature
  • Nature of the reservoir fluids produced
  • Production rates and production problems such sand, emulsions, etc.
  • Effective reservoir permeability, skin factor, etc.

       b. Production Test

Production test is the most complete Well Testing procedure, is necessary a complete Well Testing surface equipment for proper measurements of all the production parameters.
When the well is completed permanently, Production Test are carried out before the beginning of the production life of the well.
These tests can determine the flow rates assigned to the well according to its producing potential and their interpretation is used to optimize the reservoir management.

Production Test can be performed:

  • during the producing life of the well, in order to follow the evolution of the production parameters and improve the understanding of the reservoir;
  • on initial completion, or recompletion, to determine the capability of the well under various degree of pressure drawdown;
  • as a Long production test, extended for a long period of time to determine the response of the reservoir.