Research & application of multi-stage reaming technology to improve cementing quality

Abstract: the southern oil area of Dagang Oilfield is a complex fault block oilfield. With the development of water injection, it is in the high water cut stage, and the cementing quality rate is only about 55%. The analysis shows that the existence of thick filter cake or cuttings bed affects the cementing quality of the second interface. Therefore, this paper designs a special well cleaning tool, puts forward the multi-stage reaming technology, and expounds the principle and technical measures. The technology has been used in 4 wells in the south of Dagang Oilfield, and the cementing quality is high. This study provides a feasible and effective method to improve the cementing quality of the second interface.

Preface

The southern part of Dagang Oilfield is a complex fault block oilfield. With the development of water injection, it is in the high water cut stage, and the cementing quality rate is only about 55%. This is mainly due to the increase of sandstone porosity in the main reservoir after water drive development, which leads to the decrease of sandstone strength, resulting in the formation of thick filter cake in the wellbore during drilling; in addition, due to the limitation of surface conditions, more and more directional wells are developed, and the cuttings bed is easy to form in the well section with a deviation angle of 45 ° to 65 ° during drilling. However, both thick filter cake and cuttings bed seriously affect the cementing quality of the second interface.

In order to solve the problem of poor cementing quality of the second interface, turbulent displacement, movable casing, casing accessories, isolation fluid and special flushing fluid are used at home and abroad, but the effect is very little. Therefore, in order to solve the problem of poor cementing quality of the second interface in the south of Dagang Oilfield, a new type of well cleaning tool was designed, the multi-stage reaming technology based on the well cleaning tool was carried out, the virtual filter cake or cuttings bed on the wellbore was removed, and the pilot test of four wells was carried out, and the cementing quality of the second interface reached high quality.