Technical Specifications

Carbon and Alloy Wirelines A standard practice of Danum Well Services is to ensure that both carbon and alloy wires are independently certified. This allows us to comply with DIN specification 50049.3.1.B. An independent laboratory composes testing carried out on all Wirelines. Original samples of each wire supplied by Danum Well Services are kept for six years at our premises. This allows both the operator of the wire and Danum to review samples if any problems occur to the wire whilst in service. Below are illustrations and brief explanations of types of wire breaks or fractures and how these may be caused.   Snarl Type Fracture: This type of fracture is caused by a loop being allowed to form in the wire without the loop being able to unfold. Poor handling or a mishap down well, such as overrunning, can cause this. The material of the wire is not connected to this type of fracture.   Shear Type Tensile Overload Break: The title itself suggests the cause of this type of break. Quite simply the wire has had too great a load placed upon it and has simply broken through the excessive weight applied.   Hydrogen Embrittlement: This fracture is found on carbon steel slicklines and is caused by sour well conditions. We would suggest that if this type of fracture is found you should look at using a different type of material to avoid any unwanted down time.   Loss In Diameter: This photograph demonstrates what can happen to a wire when it has been stretched; in this case being passed around a sheave under too high a load caused the break. It is a misconception that all 0.125" super alloy slicklines offer the same breaking loads. The GD31MO supplied by Danum Well Services has been in service for over 9 years and provides exceptional results, determined by the extra breaking load offered by the GD31MO. In terms of breaking load the GD31MO offers valuable extra pounds (lbs) in comparison to the UK leading suppliers product. This provides a greater window for an operator to perform required operations in the field. The table below highlights the differences in breaking load between Danum Well Services and the UK leading supplier. Examples of Nominal Breaking Loads   GD Canline UK Leading Supplier Diameter 0.108" 2150 lbs 2030 lbs Diameter 0.125" 2638 lbs 2560 lbs (H.S.) 0.125" 2830 lbs N/A The GD31MO offers a further breaking load of a minimum 270 lbs. The High Strength option is only supplied on the 0.125".

Corrosion Testing Results

The laboratory has carried out corrosion tests on wireline samples on number of occasions. The report pulls together the results obtained on several materials using modified NACE room temperature stress corrosion test solution.

The standard NACE room temperature test solution consist of a 25%NaCl solution to which is added 0.5% Acetic acid and which is then saturated with H²S. The solution that was used for the present work was similar to the above but with but with the important difference that the acetic acid was replaced with 1%HCl.

This modification makes the test solution considerably more agressive than the original NACE solution, and over a number of years the results which have been obtained using it have been found to better reflect the performance of variuos alloys in the field. The specimens which were used in the test, each consisted of "U" shaped loop of wire bent around its own diameter and locked in positionby twisting the end. the samples were degreased in Petroleum Ether prior to exposure.

Results:

The test on the 316SS was terminated after 240hrs, where the specimens were found to exibit cracs.

The test on Duplex Type was terminated after 335hrs, because although the specimens had not broken, they were found to be dissolving in the solution.

In case of 27Cr/34Nickel specimens, circumferential black lines had formed after 250hrs on the surface of the wire in the region of the bend. After 350hrs the specimens had developed cracks and the surface on the outside of the bend had begun to crumble.

The specimens of UNS8926/GD31MO were undamaged although discoloured after 1050hrs when the test was terminated.