At Shengquan district of Turpan-Hami oil fields, collapsing salt-gypsous strata are encountered in oil drilling and Cl - content in the drilling fluids used is high (2×10 4～5×10 4 mg/L and up to 7.8×10 4 mg/L in some cases). The quality of well cementing jobs performed is unsatisfactory.
2. Establishing 6 primary bonding interface microstructure models, revealing the mechanism why the cement mantle in well cementation is out of work and the mechanism how the YLD-1 bridging particle increase the bonding strength on interface, thereby, presents the enhanced microstructure models on the bonding interface and the mechanism of reinforced bonding strength on interface.
The cementing materials are Jiahua class G cement, 35% silica flour (BWOC) , anti-migration additive G60-S and high temperature retarder H-88. Double plugs are used during cementing and the slurry density designed is at 1. 87 g/cm3. The average density is 1. 83 g/cm3 in cementing job.
Based on the analysis of the difficulties of φ177.8mm and φ127.0mm liner cementing job in Banshen 32 Well of Dagang Oilfield, the paper introduces the technical measures and operation technology in detail.
Considered the requirement of cementing job and protection the coal reservoir,it was proposed that the desired cementing slurry density boundary should be(1.20)-(1.60)g/cm~3,at the same time,the thick cement slurry should be under the low return rate,(0.5)-0.8 m/s,in the cementing operation.
In particular, the role of osmosis in well flushing and cementing processes was noted in study by N.
The described system not only allows cementing under vacuum, it also permits to optimise drainage during surgery.
HPCH is a composite system, which is composed of cementitious and auxiliary cementing materials, composite additives, abrasion resistance component (aggregate) and pigment.
The density of material structure, bonding capacity of cementitious material to the abrasion-resisting component and the corrosion resistance are greatly and effectively improved by adding the auxiliary cementing materials and compound additives.
Severe leakage is confirmed at the interface between hardened slurries and steel tube during the dynamically curing process, which induces the quick loss of cementing property of slurries.