Modified silicate steam diversion agent for use in sanding steam huff-puff wells

The steam diversion agent(SDA) presented was developed for use in steam huff-puff heavy oil wells in Gudong with steam breakthrough occured in pay layers and sanding problems encountered in the later stage of a production cycle. The basic material of the SDA was a grade G oilwell cement, the surfaces of which were modified by 10% metal oxides and 5% silicone: a mixture of petroleum resin + powdered Al + benzole acid + plant fiber 0. 1-0. 3 mm in diameter and 5-10 mm long in mass ratios of 8:0. 05: 1: 1.5 was taken as permeability enhancing agent at dosage 60% of mass of the basic material. The working fluid was prepared in fresh water. The optimized parameters were: water to modified cement ratio 0.6; curing temperature 60°C; and curing time 72 hrs. The cured compounded modified cement had permeability to oil phase, kersene, 0. 01219 μm2 and compression strength 6.43 MPa and the two characteristics changed to > 1. 0 μm2 and ∼5 MPa after treating by steam at 300°C and kerosene at 60°C. For a set of sand packed tubes in paralell treated by this SDA, the proportion of steam intake of high and low permeability sand packed tubes was dropped from 2.4:1 to 1:1.9. This SDA was successfully used in two steam huff-puff wells with 8 and 10 m3 of working fluid injected per well.