Research And Application Of Elasto-Toughness Slurry In Shale Gas Well Of Jiaoshiba

With the high-efficient exploration and development of shale gas in Jiaoshiba shale gas field,such as the annual production capacity of 10 billion party natural gas,Changning-Weiyuan national shale gas industry demonstration area,China’s energy structure is constantly changing.As an unconventional reservoir of self-generation and self-storage,commercial development of shale gas benefits from the continuous progress of cluster horizontal wells and large-scale fracturing technology.But large scale fracturing construction has large displacement and large scale,and produces alternating load in cement paste.Conventional cement paste has high brittleness and poor impact resistance,which may lead to cracks and breakage in fracturing,thus destroying the integrity of the whole wellbore.Zhongyuan Cementing Company undertakes all the cementing operations of Jiaoye 1HF well and Fuye 1 well,but the slurry system used in the production layer is outsourced.As the petroleum industry enters the "extremely cold period",in order to control the cost,the cost must be reduced and the efficiency must be increased.Therefore,Zhongyuan Cementing Company specially aims at the core cement outside the coke dam area.The elastic cement slurry system can meet the requirements of the design of the cement slurry in the coke-stone dam project area.In this study,filtrate reducer ZYJ is synthesized by aqueous solution polymerizing using the sorbent monomer AM,the temperature resistant monomer AMPS and the hydration monomer AA.And retarder ZYH is synthesized using the temperature resistant monomer AMPS,monomer AA and TA,and complex monomer EDP.The laboratory optimal synthesis process of filtrate reducer and the retarder is determined,considering the effect of cement loss control performance and retardation performance which caused by changing the monomer ratio,reaction temperature,reaction time,initiator addition amount and system p H value.The laboratory compatibility of these agents is evaluated.The result shows the high-strength low-density cement slurry system and the elastic cement slurry system using the agents synthesized,with adjustable cement thickening time,>14MPa strength,≤7.5MPa elastic modulus,and well sedimentation stability,meet the requirements of the cementing design in the Jiaoshiba working area.The cement slurry system developed in this study has applied 30 wells in Jiaoshiba working area,concluding the Jiaoye 38-1HF well and Jiaoye 19-4HF well.In these wells,the qualified rate of cementing quality has reached 100%,the excellent rate is 96.77%,and the rate annulus zone with pressure is 40% reduced from the previous 82.4%.The field application shows that the cement slurry system developed in this study,with excellent performance indexes and good on-site application effect,better solves the problem of low cementing quality and high rate annulus zone with pressure in the Jiaoshiba work area.And the cement system has good promotion and application prospect for the development of shale gas.