Published May 2011
Horizon and oil occurrence depth influence on “Neft Dashlary” field oil
N.M.VikhlyayevaThe results of investigations of oils from new wells of Neft Dashlary oil field are presented in the article in the view of influence of the horizon and occurrence depth on the quality of the oil. During the last decade there have been investigated 2 samples of trade oil and 36 oils from new wells of the above mentioned oilfield that occur in different depths and horizons (X, SP, KS, PKS, NKP, IKG, KaS). It has been determined that the oil samples are low-sulphur, differ on contents of the resins, asphaltenes and hard paraffin and contain 3.09-9.23% of resins, 0.04-0.39% of asphaltenes and 0.62-10.65% of paraffin. Neft Dashlary oil field is situated in Absheron oil-gas region. The Productive Series (PS) of the region is divided into 3 levels: lower, middle and upper one; and in each of these levels there are suits such as: Kas, PKS, KS, NKP, NKG, SP, etc. Each suite of the PS is a set of differently-sized sandy-clay layers sequence. From this standpoint, the generalization of the results of investigating oils of different wells of Neft Dashlary oil field has shown that oils from different wells of the same horizon, as well as oils from different horizons differ by their physicochemical properties. Oils of X and SP horizons that are low in paraffin differ from the oils of other horizons. Oils of NKP horizon are mostly high in paraffin; the content of paraffin increases with the increase of the occurrence depth until 1796 m in NKP horizon oils. In KaS oils, the more occurrence depth, the higher the oils in paraffin, and lower in resins; by contrast, in PKS-1 and PKS-2 oils, paraffin content lessens, and resins content raises. Therefore, analysis of oils by suits will make it possible to understand to what degree geological boundaries, i.e. boundaries between the times of different sediments, may influence the quality of the oils in those suits.
