Wellsite geohazard and pressure prediction - Fugro Geoconsulting and Ikon Science

Executive Summary

Wellsite geohazards are a demonstrable problem in many basins around the world, and often manifest as shallow gas or shallow water inflows. These features can be identified from seismic amplitude data. However, the magnitude of the pore pressure is compromised due to a general lack of log and other data due to the depth of the 20 inch casing shoe (which can be >4000 feet in some basins). Understanding the magnitude of this anomalous pressure has implications for site investigation but also for planning of wells to assess deeper stratigraphic target.

Geohazards and geopressure are intimately linked within the overburden; it is this real-world connection that forms the basis for a collaborative approach to their analysis and understanding. Both geohazards and geopressure have to be considered when planning a well: Fugro Geoconsulting and Ikon Science say that it makes sense for these factors to be assessed and considered together in a single project, with integrated deliverables to the client.

A combined Approach to Pre-drilling Wellsite Analysis

A combined approach to pre-drilling wellsite analysis

We seek to provide an integrated service whereby Ikon will utilise Fugro’s analysis and interpretation to enable a more complete and potentially more accurate study of pore pressure in the shallow section, and consequently the deeper section as well. A reciprocal supply of the Ikon results to Fugro will allow refinement and enhancement of the geohazard interpretation.

  • Improves visualisation of geohazards via access to reprocessed high resolution amplitude seismic data
  • Identification of shallow faults that could cause charging of sands 
  • More accurate seismic facies and net/gross from inversion using Ikon’s Ji-Fi or EEI 
  • Improved time/depth model from associated seismic velocity model to better predict rates of sedimentation 
  • Improved shallow velocities to better predict pore pressures

The overall aim is to add the strengths of each company to provide a more complete, integrated service for well planning and site investigation.

  • Better definition of normal or hydrostatic pressure to define normal compaction, the baseline for overpressure 
  • The creation of a more reliable shallow overburden model
  • Reconciliation of fully petrophysically-interpreted logs with seismic amplitudes and pressure interpretation
  • Any geophysical and geotechnical data that have been used by Fugro in well site geohazards studies will be available as inputs to pore pressure prediction. These may include high resolution velocity analyses from high resolution data and short offset reprocessed seismic, geotechnical samples and piezoprobe data

Improved resolution through short-offset reprocessing

About Fugro GeoConsulting in this partnership

Fugro provide consultancy services for the interpretation of shallow section marine geophysical and geotechnical data. One of the main markets for this service is the study of top-hole drilling conditions and the prediction and analysis of wellsite geohazards. Many of these studies involve data collected by Fugro companies around the world, but for deep water wells the primary data set is normally existing exploration 3D seismic, which is often reprocessed to offer better resolution. To service this consultancy market, and to provide support to shallow section seismic studies worldwide, Fugro GeoConsulting maintains a group that specialises in seismic interpretation and drilling geohazards that is part of a wider European geoscience consultancy capability. Similar GeoConsulting capabilities are maintained in Fugro’s Houston office. Fugro Geoconsulting is also able to provide geotechnical engineering advice on the foundation aspects to offshore drilling. For example, surface conductor installation studies for deep water wells, where recommendations can be made on the depth of conductor required based on axial and lateral capacity requirements as well as soil fracture analysis and guidance on the installation method.

To read more from Fugro on their Geohazard studies, please visit their website. 

About Ikon Science in this partnership

Ikon Science is a global leader in the provision of pressure prediction (pore pressure, fracture gradient, wellbore stability). The Company offers worldwide experience of geoprediction based on analysis of multiple relevant data types coupled with deep understanding of the relevant geological history and setting. They employ methods which were developed within Ikon GeoPressure to handle the challenges of prediction in high temperature settings, as well as carbonate-dominated and sub-salt settings. Interpretation is supported by use of proprietary, licensable software (RokDoc GeoPressure) which includes a well database and pressure plotting tool (PressureView). Ikon GeoPressure has its main group located in Durham, UK but with experienced interpretation groups in North America and SE Asia. Over the past 12 years, Ikon GeoPressure has specialised in the delivery of regional pressure analysis – comprehensive and authoritative reports and maps at basin scale – now covering all the high pressure regions of north-west Europe, as well as the Niger Delta, Gulf of Mexico, East Coast of Canada and the north-west Australian Shelf. The regional approach to geological understanding taken by Ikon closely reflects the approach to shallow hazards taken by Fugro.

To find out more about this service and the key interactions between theFugro GeoConsulting and Ikon Science teams, please contact us now.