IN BRIEF
Our land projects range from a few hundred to several thousand contractor crew members. To minimise LTIs (lost time incidents), all our personnel operate under the most rigorous HSSE regime.
Teams working together through long periods, and large survey areas, will need to overcome many logistical issues as a matter of course. Our independent QC and project management experience, adopts the pre-emptive avoidance of personal and technical risk.
Having managed projects over many years, we know to expect the unexpected and to prepare and plan for every eventuality. For example, if an emergency should require switching consultants in the field, we can manage these changes easily.
Each land seismic QC/QA team member has a wealth of practical experience. Our project management skills enable us to co-ordinate the entire project cycle, no matter how large or small, working closely with you and the contractor to ensure the desired outcome is achieved. The Geo People really work as a team and enjoy working together and with you.
The Geo People's experience of desert, jungle, savannah, mountains and forests terrains and urban terrains, means we achieve success for your seismic project, whatever the terrain.
IN DETAIL
Project management
To project manage land seismic, it is necessary to provide the process and activity of planning, organising, motivating, and controlling resources, procedures and protocols to achieve the client's specific goals. Our project manager is often a client representative, who has to determine and implement the exact needs of the client.
Many variable factors exist in a seismic project, resulting in significant investment risk. Our project management is able to minimise that risk. The project manager’s role varies from project to project but typically encompasses the following:
The ability to adapt to the various internal procedures of the contracting party, and to form close links with the nominated representatives, is essential in ensuring that the key issues of cost, time, quality and above all, client satisfaction, can be realised.
Land seismic acquisition QC/QA
Our acquisition QCs operate in 2D, 3D, and 4D land environments, as well as transition zone and land VSP surveys.
QA/QC for land acquisition is the combination of quality assurance, the process or set of processes used to measure and assure the quality of a product, and quality control, the process of meeting products and services to consumer expectations. Quality assurance is process oriented and focuses on defect prevention, whereas quality control is product oriented and focuses on defect identification.
Our land acquisition QC/QA has responsibility for the overall quality of the seismic and positioning data. In addition to this role, they often also adopt an HSSE QA/QC role, in place of a reserved HSSE consultant. A QC/QA has deep knowledge of positioning control and geophysics, as well as field experience. They are able to understand a project holistically, knowing how each factor will affect the final dataset and to what extent. An acquisition QC/QA will increase the value of the data, not just by being an extra pair of eyes and ears, but by bringing know-how from other surveys, and from working with major operators.
The experience our QC/QA offers will also benefit the contractor, especially the less experienced ones, as many potential errors do not have to be learnt firsthand, at cost. The consultant is also quickly aware and can issue suitable warnings, should activities begin to stray from optimum.
Before the start of your survey, our acquisition QC will offer to meet face-to-face with the client. This will allow the best understanding of the client's objectives and the contractor’s capabilities, so that potential technical, logistical, and HSSE difficulties can be pre-empted and avoided.
Positioning QC/QA & surveying
The Geo People provides survey QC/QA services for land 2D, 3D and 4D land, TZ seismic and onshore pipeline inspection.
For seismic acquisition, navigators and engineers need to know their position with absolute accuracy. Our positioning QC/QA consultant for land and transition zone survey has responsibility for checking the position of the seismic data. They will also verify start-up procedure and check the preliminary and final SPS data, prior to its final acceptance by the client.
On 2D land surveys, the survey QC frequently oversees the construction of GPS control networks using RTK GPS methods to enable the accurate positioning of any wells before plotting the designed program lines, relative to the true well positions.
Seismic data processing & QC/QA for land
As well as land and TZ field seismic processing QC, The Geo People provides specialist seismic processing, seismic data processing QC, and in-house seismic processing management QC.
The sequence of events in seismic processing are split into three areas namely, deconvolution, common mid-point (CMP) or common depth point (CDP) stacking and finally, migration. Deconvolution, the process which reduces the received wavelet to a spike, increases the resolution of the seismic data and attenuates short period multiples, exposing the first reflections. The multisampled data is averaged in the stacking process and finally, in migration, the data are re-positioned to the place where it originated from as opposed to where it was recorded at the surface.
Knowledge of the geology before the survey takes place and having the presence of a geophysicist QC in the field enables the client to obtain migrated data in areas of importance prior it to all being processed months later by a processing house, saving the operator much time. In land seismic data processing (unlike marine), static corrections have to be applied to account for the differences in height between the source and receiver positions. Later, further residual statics corrections have to be made to compensate for the variable velocity of sound in the near-surface, all important to get right in the field.
To make seismic processing as cost-effective as possible, we need to look briefly at three main seismic data processing methods, namely:
The deconvolution and stacking processing is best conducted out in the field, as the logistics are easier and also allows the processing flow to feed back quickly, to improve the survey process.
The migration processing will normally take place after the survey. However, if the contractor has suitable facilities and the client representative is sufficiently qualified and experienced then another, quicker form of migration processing can also take place out in the field when the survey is still on-going, in the form of a smaller migrated cube. This can save time and expense for the operator, as the rig plant can be approximately positioned, prior to the full survey result, instead of the operator having to wait for the off-site migration processing to be fully completed.
The degree of the complexity of seismic processing acquired by the operator in the field is dependent on the processing capability of the contractor, the skill levels of the contractor (and independent consultant), and the readiness of the operator to invest in this process.
Seismic processing is one of the biggest reasons for time delays faced by operators before making decisions on where to drill. The actual cost depends on the physical processing power required to compute the enormous amount of data, making the right choices for processing and effective supervision, thus ensuring that whole batches of data do not to have to be re-processed.
Technical audits for land
The benefits of technical auditing are as follows:
A technical audit (TA) for land seismic is performed by our auditors, who evaluate deficiencies or areas of improvement in a process, system or proposal. Technical audits cover the technical aspects of the project implemented in the organization.
The Geo People undertakes independent technical audits to analyse the technical performance of land seismic survey crews.
Pre-survey and post-survey testing is conducted on the survey recording, energy source and survey equipment. The survey control is audited, the acquisition reviewed and the processing of field survey data as well as evaluation and approval of survey equipment is all carried out prior to start-up.
GPS static control networks, equipment checks, and calibration tests on GPS receivers are all reviewed. The type of tests used include relative sensitivity tests, noise/distortion, and peak particle velocity observations for vibroseis and explosive sources. Importantly, at random times, acquisition parameter specifications are checked and the technical part of contracts are evaluated as equipment can go wrong at any time.