COMPLICATIONS IN THE WELLS WITH LOW BOTTOMHOLE PRESSURE

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-98-8 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 11, 97-102 pp, DOI: 10.5593/sgem2017/11/S01.012

ABSTRACT

The article presents data management results of repair works performed in the wells with different values of bottom-hole pressure. Repairs performed during the last ten years in the wells drilled in the Tournaisian, Tula, Bashkirian, and Verey deposits have been involved into a special statistical analysis. The authors provide an assessment of possible risks for control and operation of wells with low bottom-hole pressure on the basis of their study experience. The main purpose of the analysis was to determine the degree of the low bottom-hole pressures influence on the increase of problems and failures in the wells. The results of comparing two categories of repairs have shown that, despite the theoretical assumptions of the possible impact, statistical analysis did not reveal regular increase in the number of operational failures at low bottom-hole pressures. The results of the statistical analysis of the data related to well operation proved that low bottom-hole pressure in the wells considered were the result of low production rate and low productivity factor. At the same time, increase in number of operational failures in the wells with high downhole pressures is typical for wells with large flow rates. Large-scale experiments of decreasing the bottom-hole pressure in the wells with relatively high rates of productivity could make it possible to consider in detail the impact of downhole pressure on repair and workover operations, since in this case low bottom-hole pressure is not a consequence of low productivity of the wells.

Keywords: low bottom-hole pressure, curve, workover, complications, production rate