Optimization And Application Of Oil-water Well Cement Seal Technique In Tuha Oilfield

Tuha Oilfield is a typical “low pressure, low porosity and low permeability” oil and gas field whose reservoirs are multi-style and complex. The formation situation is more and more complex after nearly two decades of high-speed development, and the number of the channeling wells is more and more. The water injected can not reach the target zone because of the casing deformation and damage, resulting in a low efficiency of water flooding and the loss of potential oil reserves and production capacity. Therefore, it is imperative to research and handle the well channeling. The cement seal technique is optimized to plug the water channeling on the basis of comprehensive analysis of mechanical and chemical channeling plugging technique. The optimized technique is easy to operate, low-cost, safe and convenient.The cement seal construction date were counted and analyzed to improve the success rate of the cement seal technique used in Tuha oilfield. The influence factors have been summarized from the analysis, which are plugging agent factor, construction process control factor and squeeze-seal design factor. On this basis, the cement seal technique was optimized from the seal design and squeeze control techniques. The plugging agent, additives, squeeze-seal equipment, squeeze cementing parameters and squeeze-seal control technique have all been optimized, and the channeling plug technique applicable Tuha oilfield—cement seal technique has been got. The field application results show that the optimized cement seal technique can improve the construction effective rate from 60.6% to 81.8%, and the input-output rate can reach 1:3.