Geotechnical Services

Our Expertise:

Whilst ROS as a name does not have any evidence of completing service in the oil and gas industry, the company is run by experienced professionals very well known in the Oil and Gas industry. Our workforce is multinational and resource rich with experience and diversity. A resource from which we provide our clients and partners with the specific skills and knowledge they need. Our professionals have experience working for multinational companies in Nigeria and in over twelve countries across three continents.

Key Capabilities

Feed Studies

Front End Engineering and Design encompasses the conceptual design and basic engineering phases of a project lifecycle. During the field stage of a Subsea field development, ROS can:

Characterise the soil and seabed conditions of the site (both offshore and near shore).

Perform a geo-hazard assessment of the site.

Carryout preliminary foundation design for the Subsea structures including pipeline end termination, manifold, Subsea intervention  valves, pre delivery skids, riser bases, well head protection structures and pipeline crossing support to mention a few in accordance with relevant codes of practice.

Carryout constructability/installability assessment for Subsea assets including pipelines, piles and gravity based structures.

Carryout geotechnical desk studies in the absence of site specific geotechnical data.

Pipe-soil interaction expertise and advice.

Foundation Design

Our professionals have over 30 years experience in the design of foundations for offshore structures. As projects continue to move into more challenging areas, the design requirements and ground conditions become more onerous. In deep water environments, traditional foundations are expensive and consideration needs to be given to novel foundation solutions such as suction anchors, plate anchors or finned piles. ROS can offer a complete foundation design solution or can check designs carried out by 3rd parties on behalf of our clients.

Our foundation design expertise includes:

Design of gravity based foundations (GBS) for subsea structures including PLETs including bearing, sliding, overturning and  settlement check.

Design of suction cans for manifolds, FPSO Mooring and other subsea structures including axial, lateral and rotational capacity.

Design of pin-pile foundations including axial and lateral pile capacity.

Design of drag anchors including estimating drag and embedment distances.

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Foundation Installation Check

ROS provide Subsea structures installation analysis including the following:

Pile Drive-ability Analysis including predicting the soil resistance to driving (SRD), determining a suitable hammer size required to efficiently drive the pile to full penetration (no refusal), estimating the blow count of a pile under one or more assumed ultimate resistance values and other dynamic resistance parameters giving a hammer and driving system as well as determining the compressive and tensile driving stresses and fatigue damage in the pile during driving.

Pile stability and stick-up analysis prior to driving.

Suction pile installation and extraction analysis.

Breakout loads/forces for recovery/re-positioning of sub-sea structures.

Drag anchor embedment and drag.

Ros Engineering Foundation Check

 

Pipe Soil Interaction

ROS also have expertise in pipe-soil interaction and can provide geotechnical analysis and advise in:

Determination of pipeline settlement taking into account dynamic/remoulding effect during installation.

Determination of axial, lateral and berm soil resistance and friction factors for pipeline in-place conditions.

Upheaval buckling analysis for pipelines for buried pipelines.

Ros Engineering Pipe Soil Interaction


 

Pipeline Trench Engineering & Risk Assesment

In circumstances where pipelines have to be trenched and backfilled, ROS can provide expertise to our clients:

Determine the right trenching tool suitable for the soil conditions at the site selecting from a wide range of jetting, cutting and ploughing tools available to the market;

Carryout trenching risks assessment including assessing risk of not achieving the required trenching specification, risk of product damage or schedule risks to the project as well as recommending mitigations to reduce the risk to ALARP;

Carryout trenching engineering analysis including an assessment of the bathymetry, seabed features and shallow soil conditions along the pipeline route, determining the right jet trencher configuration to ensure specifications are met, predicting the trenching speeds anticipated and assessing the number of trenching passes required.

Ros Engineering Pipeline Trenching


 

Site Evaluation

Geotechnical input at the planning stage of a project or field development is necessary to ensure that all geotechnical and soils related risks are identified at an early stage. ROS can:

Perform desk studies to assess the feasibility/suitability of the proposed sites for Field development.

Develop a conceptual geological model for the site.

Provide an assessment of geohazards and constraints relevant to the planned construction or engineering application of the site.

Outline scope to optimise the findings of a site specific survey.

Review site investigation and desk study reports produced for our clients by 3rd parties.

Dredging

In certain circumstances, seabed dredging is required to prepare seabed (flatten seabed profiles or to remove soil to allow access to a subsea asset. ROS can assist our clients by:

Preparing a dredging scope of work document to be adhered to by the dredging contractors.

Recommending the best method and tools for dredging to ensure the requirements of the project are met.

Reviewing technical dredging proposals to assess suitability for the work scope.

ros engineering dredging


Rock Dumping

In certain circumstances Rockdumping is required on pipelines and subsea structures to mitigate upheaval buckling and minimise scour (around structures) or in some cases reduce the impact of snag loads on the structure. If Rockdumping forms a part of a project’s workscope, ROS can;

Prepare a rockdump scope of work for our clients after reviewing the Rockdumping needs of the project.

Assess proposals submitted by Rockdumping contractors.

Review rock stability and rock impact calculations.

Assess rock quantity requirements for the project including rock grading requirements.

Assess suitability of proposed Rockdumping methodologies.