Tahe Oilfield Wellbore Treatment And Process Light Oil Wells

Tahe Oilfield is located in Gobi desert in the northern part of Tarim Basin. The Ordovician reservoir type, oil distribution and the causes of the reservoir are extremely complex because of the impact of the multi-phase accumulation and the reservoir heterogeneity.The eighth area of Tahe Oilfield and some external light crude oil wells almost contain wax, heavy oil ingredients such as glial, asphaltene,and also contain mechanical impurities elements such as sludge, oil sands, etc. These components interact to make a result that they coalesce easily and block the production string in the production process,causing wells quit flowing, at the same time the operating costs increase and the operating procedures will be more complicated. In order to prevent oil wax and ensure the normal oil production, conventional mechanical methods are mainly adopted currently to clean the paraffin. As the operations are much more frequent, the average scratch cycle has been shortened to 3 days,such as well S86, TK743, TK836CH, TK840, resulting in increased production costs, at the same time, hydrogen sulphide is very dangerous.In this paper, a survey has been conducted about the law of the precipitation of glial, asphaltene, wax and the technology of wax cleanness and protection at home and abroad currently. Also,the components, the causes and the influencing factors of the precipitates in Tahe Oilfield have been analyzed,after that, an enormous amount of experiments have been carried out and the results obtained are as follows:(1) It is concluded that the precipitates contain not only wax but glial and asphaltene through the analysis of the atomic absorption spectrometry, atomic emission spectrometry, XRD diffraction analysis, infrared spectroscopy and electron microscopy scanning.(2) The precipitation mechanisms of the glial, wax and asphaltene and impact factors have been definited through a large number of experimental studies.(3) Two kinds of precipitate deposition inhibitor SW-1 and SW-2 and the corresponding series of SWQ precipitate scavenger have been developed, and there effect has been evaluated.(4) The light-oil well shaft Process was developed to suit the well characteristics of Tahe Oilfield.