To assess and prevent instability risks in future wells to be drilled , which will allow assessing the risks associated with building up inclination angles and azimuths, formulating and designing a program listing the weights and path-dependent types of muds and slurries, as well as determining well designs. Modeling results will help bypass the risks associated with absorptions and gas kicks as well as simulate the fracking process, including multistage fracking, to better stimulate the vertical and horizontal wells in the fields.
BASIC INFORMATION ON THE OBJECT UNDER EVALUATION
There are seven (07) vertical wells drilled.
The following well data available for the study: Daily Drilling Reports, Mud reports, Open hole & cased hole Logging and Geological data, etc…
The scope of 3D seismic acquisition covers ~ 600 km².
DATA acquisition and QA/QC
- For 07 vertical wells already drilled in these fields: make sure that available data are enough to built-up 1D Mechanical Earth Model, that is wells are old, we may be in lack of mandatory data as compressional and shear slownesses, GR, density, calibration data (coring or Frac data).
- For the upcoming 24 wells to be drilled, make sure to overcome the lack of data that may exist in the previous drilling campaign, and make sure as well to run suitable tool for data acquisition (sonic scanner is highly recommended, coring data, triaxial test, lab coring test.
- The contractor shall make sure to have all mandatory data for a correct 1D Mechanical Earth Model built will be available, with a full package of data calibration as well.
TASKS TO BE TAKEN ON (SCOPE OF WORK) :
- Perform the 1D Geomechanical Modeling of the designated fields to streamline the drilling processes and opt for the best fracking and completion designs.
- Build a geomechanical model to understand the present in-situ stress, rock properties and formation pressures within designated Fields.
- Evaluate geological stresses effect on the borehole stability and provide recommendations for well trajectories and azimuth, identify zone or area of high breakdown pressure.
- Opt for the best drilling technique, including specific weights, for cementing and mud-conditioning operations and mud windows.
- Recommendation for KOP of horizontal wells.
- Evaluate borehole stability of horizontal wells drilled along SHmax and drilled along Shmin, that is for multi-stage purposes it is recommended to drill along Shmin to have transversals fractures, however this can lean and require to add mud weight, make to run sensitivity analysis for well trajectory, mud weight, bore hole stability, and highlight the major operational problems as well breakout, loses, or other drilling problems (if any).
- Select probable/acceptable completion designs: multihole drilling, horizontal drilling (uprising wellbore, subhorizontal wellbore, top-down wellbore), and horizontal drilling with multistage fracking.
- Optimize future well designs and completions, including well courses and casing shoe running depths, by mitigating the risks associated with wellbore collapse, lost returns, absorptions and kicks, stuck drilling assemblies, maximum permissible meterages for various parameters (such as PVT, permeability and porosity, etc.) during horizontal drilling. Provide recommendations to reduce the risk of blowouts and lost returns, absorptions, and kicks during well drilling.
- Make sure to consider the value of breakdown pressure of hydraulic fracturing operation in completion equipment’s design and rating.
- Assessment of reservoir degradation and sand production during well operation depending on water cut and draw down, provide recommendations.
- Compile input data to design the fracking process, including multistage fracking during horizontal drilling.
- Make recommendations for number of cluster, spacing for Hz multi-stage fracturing.
- Develop the optimum fracking design for existing wells subject to their current condition and geologic hazards.
- Develop the optimum (multistage) fracking design for future production wells subject to probable completion designs. Evaluate whether re-fracturing operations are fit for purpose and how often they are done, list related technology in use.
- Provide recommendations for proppant in use.
- Prepare recommendations to opt for completions with a view to the preferred fracking design and possible sand production.
- Create a work program to retest existing wells (with side-tracking and fracking).
The consultant shall provide / have:
– Experience in similar works.
– Experience in similar projects over the past 5 years.
– Availability of licenses or your own software to perform all listed tasks.
– Availability of methods, approaches, technologies to perform all listed tasks.
– Experience in analysis of data of wellhead high-frequency monitoring of fracking pressure to confirm the location of fracking initiation and localize fracking cracks.
– The potential supplier shall immediately inform the Company of any methodological or technical difficulties arising in the performance of the works.
– The potential consultant shall not disclose any information received from the Company or the results of processing of information received from the Company, or the results of the Company’s core analysis to any third party without the Company’s written consent.
– The works must be performed using the basic laws of reservoir physics, multiphase media mechanics, and principles of hydrocarbon deposit development, using available experience and existing tools of operational forecasting of development indicators and technological conditions of well operation, as well as using mathematical and computer modeling. The works should make maximum use of the information provided by the Company. Including but not limited to: single-phase flow studies on core, porosity and permeability studies on core.