- Formation Sampling And Analyzing
Collection of drilled solids at lagged specified intervals
Preparation of samples with proper sieves (5mm, 1mm, 0.5mm)
Sample catching, washing with proper agents, sieving, and drying cuttings in compliance with the requirements stipulated in the well Location Report (unwashed, washed and dried, numbering).
- Bagging and labeling of wet (unwashed and washed) and dried sample
Fluorescence determination on lightly washed cuttings as well fluorescence and cut determination of washed cutting in solvent.
Preparation and labeling of samples for dispatch
Determination of washable fraction and calcimetry
Microscopic examination of samples for lithological determination and percentages as well as classification of various elements minerals.
Sampling and quick analysis of all fluids produce (gas, oil, water) including formation gas and gas kicks
Characterisation of any liquid hydrocarbon samples from the flow line.
Master log geological interpretation and preparation.
Shale density trend analysis.
Preparation of reports in the Company specified format.
Geological evaluation of al data collected and computed by the mud logging system.
Correlation of cuttings lithology, gas analysis and hydrocarbon evaluation to reference material provided by Company.
Immediately liasing with Company’s representative and drillers for any abnormal evolution of expected parameters.
Annotation of charts.
Provision of daily reports and preparation of an up to date Geological Master Log.
Frequency: The Company shall specify frequency of cutting sampling
Collection: for exploratory and appraisal wells, unwashed sets and washed and dried sets are prepared for dispatched (number of sets will be specified by the Company). To ensure representative samples are collected, a cutting board shall be used at the shale shakers. Sample bags for dispatch are identified by well number and depth interval.
Washing Cuttings: for routine washing the 5mm, 2mm, 1mm and the 0.5mm size sieves are used together. Soluble salts are washed with water. Geochemical samples, if requested, are washed and packed airtight. A suitable biocide, acceptable to the Company, is added to each sample to prevent degradation of the sample.
Cutting Examination and Description: The cuttings are examined from each sieve.
Hydrocarbon Tests: three tests are made on each sample. - Natural Fluorescence
- Cut Fluorescence
- Solvent Cut Fluorescence
- Where the presence of light oil or condensate is suspected, an Acetone Water Test shall be carried out.
- Recording of Gas Shows: Trip gas, recirculated gas, background gas, and connection gas peaks are identified and annotated with correct lagged depth. a plot of gas concentration versus ROP is maintained to enable some degree of normalization of gas shows to ROP.