Ultra-Low Density Hollow Microspheres-Nitrogen Foamed Cementing Technology in Block Hangjinqi

Abstract

Hollow microspheres-nitrogen foam cementing technology with ultra-low density could potentially solve the problem of cementing leakage in Hangjinqi Block. It could also assure the one-trip safe return of cement slurry to form a complete cement sheath, and improve the cementing quality and wellbore integrity. An ultra-low density hollow microspheres-nitrogen foamed slurry with a density of 1.15-1.20 kg/L wad developed by charging nitrogen into the low-density hollow microspheres slurry system, and adding foaming agent and foam stabilizer to form a high-pressure nitrogen-charged foaming technique. The matching field choking and back pressure devices were combined with independently designed and developed mechanical nitrogen injection equipment. By doing so, the foamed cementing slurry technology with ultra-low density for pressure management and leakage control was established. The technology has been used to cement the technical casing in 5 wells in Hangjinqi Block, and in each, the slurry was safely returned one time. The average density of downhole hollow microspheres-nitrogen foamed slurry in Well JPH351 is 1.15 kg/L, the length of cemented section is 2 800.00 m, and both have excellent cementing quality. The successful development and application of ultra-low density hollow microspheres-nitrogen foamed cementing slurry technology has provided a new technical approach for addressing cementing leakage problem of low pressure wells in Hangjinqi Block and similar blocks.

AAPG Datapages/Search and Discovery Article #130002© Petroleum Drilling Techniques, Issue 3, 2018