AN initial field trial of an advanced hand-held analyser has revealed its potential for the rapid and effective testing and measurement of oil and gas drilling fluids.

Independent oil and gas exploration and production company IGas Energy plc develops onshore oil and gas fields and produces more than 2,500 barrels of oil equivalent per day from more than 100 sites across the UK, with other potential sites regularly coming under its control and management.

The company decided to enhance the production on Stockbridge oilfield and to drill three sidetracks from existing wells.

This involved new reservoir development work, which saw the re-entry of existing wells to develop new areas in the field and boost production. The side-tracks were drilled directionally and entered the formations horizontally and completed between 700 and 1,500 metres of new hole from the kick off point in the original wellbores.

MudChecker testing

An important element of the drilling covered the management and control of the mud fluids, which are designed to fulfil several critical functions including pressure control, lubrication of the wellbore, cuttings removal and hole stability.

The most fluid sensitive rock formations at the Hampshire site were the clays, which were drilled using an oil-based drilling fluid (OBM) requiring measurement at regular intervals for oil, water, solids and chloride content – regular analysis of fluid composition is a pivotal task for mud engineers during any exploration work.

To meet this need, IGas trialled the MudChecker drilling mud analyser from Salunda as a potentially beneficial alternative to the onerous and time consuming retort and titration analysis method. The analyser is the first electronic diagnostic device of its type for the fast and accurate measurement of several critical parameters of Oil-Based drilling fluids.

The Stockbridge trial involved the evaluation of an early MudChecker prototype during several test sessions as an effective way to check the drilling fluids, assessing the hand-held analyser’s capacity to provide rapid and consistent measurement of percentage oil, solid and water volumes when compared to results gained through initial retort analysis.

The trial revealed that the MudChecker, which is also simple and easy to operate, could provide fluid analysis up to six times faster than traditional methods, producing consistently accurate measurement data.

Although its early days, according to Bob Sharp, IGas mud engineer, who oversaw the project as an independent consultant to IGas, the trial has confirmed the potential of MudChecker’s capability in oil and gas exploration and production, as a viable, reliable and cost effective method, with ‘significant potential’ to effectively become a long-term test replacement to retort.

He said: “After some fine tuning, the MudChecker started to produce comparable results to that of the retort method, but far more quickly and consistently. Indeed, I would estimate that usable measurements were provided within 15 minutes when compared to the 90 minutes it took using retort analysis.”

“Moreover, the analyser is much simpler to use, which will be of benefit to mud engineers and operators. The trial revealed that it could significantly cut testing times and improve the efficiency of measuring fluid characteristics, both in the field and in mud plant activities.”

“Using the data MudChecker provides will undoubtedly improve fluids maintenance and checking during drilling activity, enabling changes in content to be made quickly and more accurately. It will also enable companies to perform tests easier and more conveniently; so potentially it should be well received by the global oil and gas industry.”

Incorporating patented, sensitive radio-frequency technology, MudChecker features an integral sensor probe that is used to test a sample to provide an accurate, real time in-field measurement of mud fluid content and temperature.

Consistent and repeatable results are quickly displayed on an integral LCD screen to indicate percentage oil, solid and water volumes. It also records the oil/water ratio (OWR), oil/brine ratio (OBR) and water-phase salinity. Control of these parameters can be critical for mud stability, as well as avoiding wellbore collapse, that might otherwise result in equipment loss or damage, and non-productive time (NPT).

The captured data can be quickly up-loaded via a USB interface to a supporting software programme and can be exported for formal record keeping and reporting. MudChecker comes in a water and solvent resistant rugged enclosure for improved onsite durability and features robust, easy-to-clean stainless steel probes. Salunda propriety software is available to log, export and print-out results quickly and accurately.

The compact analysis unit is supplied as part of a lightweight portable test kit, which includes a mains adapter with interchangeable European and USA adapters, downloadable software and a selection of spare tubes, probes, syringes and proprietary sample mixtures.