X-ray Mineral Services Ltd.
 1 Claughton Road,  COLWYN BAY,  LL29 7EF.  UK
 Tel: +44 (0)1492 535250        Fax +44 (0)1492 536463
Petroleum Industry Applications
A knowledge of the detailed mineralogy of hydrocarbon-bearing rocks is essential in the interpretation of reservoir formations for petroleum exploration and production. One of the key analytical techniques applied in this respect is X-ray Diffraction (XRD).

XRD can be used to
(1) characterise the mineralogy of whole rocks,
(2) determine the types of clay minerals,
(3) determine the types of drilling mud, and
(4) identify downhole reaction products and scales.
A major advantage of this technique is that it can be used for both qualitative identification and quantitative estimation of phases.
Whole rock analysis:
A semi-quantitative measurement of the total mineral content of a sample including a full interpretation particularly with respect to silica minerals, feldspar and carbonate compositions, evaporites (anhydrite/gypsum), zeolites and heavy minerals.
Clay-fraction quantification:
A separation and quantification of the <2 micron clay fraction phases. Treatments to identify the components include glycolation and heating to 380C and 550C. Where feasible this analysis will provide information on:
  • Kaolin polytypes eg kaolinite, dickite, nacrite and halloysite
  • The Fe:Mg ratio (Y value) of chlorites to identify chamosite or clinochlore
  • Illite polytypes 1M and 2M to help determine authigenic or detrital origin
  • Swelling clays (smectites) and mixed-layer clays eg illite/smectite, chlorite/smectite, kaolinite/smectite, serpentine/chlorite
  • Illite/smectite ratios and type of interstratification ie random, ordered and long-range, to help determine diagenetic transformation phase of illite/smectite and organic maturity levels
  • Minor and less common clays eg sepiolite and palygorskite
    •
    Identification of Scales, Drilling Mud, and Reaction Products:
    It is often necessary to identify down-hole corrosion or reaction products, scale materials, and any residual solids during petroleum production. The types of materials vary and include iron or calcium carbonates, iron oxides and sulphides, drilling mud such as bentonite or barite, and toxic reaction products. The most convenient and rapid technique often used in this case is X-ray diffraction employing a whole-rock type analysis.