新型低伤害压裂液性能评价及现场试验

EVALUATION AND APPLICATION OF NEW FRACTURING FLUID WITH LOW DAMAGE

针对川西浅层J3p气藏的低温和低压地质特征和地层返排能量有限、压裂液返排速度低、排液不彻底等诸多难点 ,以及施工过程中 ,压裂液滤失量大 ,储层水敏性粘土矿物含量高 (水敏性强 )等问题 ,文章提出对胍胶进行改性处理 ,并将生热体系引入到改性胍胶压裂液体系中 ,形成新型低伤害压裂液体系。通过对TC9 2A新型低伤害压裂液的粘度特征、流变特征、滤失、悬砂、增压、升温、助排以及对油藏岩心伤害等室内评价和龙 72井的现场应用 ,结果表明该新型低伤害压裂液不但具有自动增压、降低井筒液柱密度、表面张力低、破胶彻底、破胶液的粘度低等优点 ,还具有优良的携砂和助排能力 ,在改造低压、低渗透油气藏具有明显优势。

Aiming to the geological characteristics of low temperature and low pressure of shallow J 3p gas reservoirs in the west Sichuan, and the problems such as the limited energy of formation flow-back, the low flow-back velocity of fracturing fluid, the flow-back non-completion, the big filter loss of fracturing fluid during the job, and the high content of water-sensitive clay mineral in the reservoirs, it is proposed in the paper that the guar gum should be modified on the performance, and the heat-generating system should be introduced into the fracturing fluid with the modified guar gum to form a new fracturing fluid with low damage. By in-house evaluation of TC9-2A new fracturing fluid with low damage on viscosity, rheological property, filter loss, sand suspension, pressure increase, temperature increase, flow-back assisting, and core damaging, etc., and field application at Well Long 72, the results indicate the new fracturing fluid with low damage has not only the advantages such as auto-increasing pressure, decreasing fluid density in well-bore, reducing surface tension, breaking gel entirely, and lowering viscosity of the gel-breaking fluid, but also the excellent ability of sand carrying and flow-back assisting. It benefits stimulation of oil and gas reservoirs with low pressure and low permeability obviously.