When wells were drilled in Sichuan and Chongqing oil and gas fields,various problems were encountered such as a big difference in the permeability between sandstone and carbonate reservoirs,hydration swelling which easily occurred in clay and shale formations,sour gas reservoirs with high temperature,abnormal high pressure,and a high content of H2S and CO2,and deep wells with high temperature and high salinity.Therefore,according to the requirement of HSE management,some technical measures were taken for completion and workover work under different well conditions at specific strata.First,a specific scheme for completion and killing fluid system was designed.Second,new additives with a high performance were developed including thickener,viscosity increaser,synergist,fluid loss additive,inorganic salt crystalline inhibitor,temperature stabilizer,anti-scaling agent,desulfurizing agent,and corrosion inhibitor.Third,materials with biological degradability and low toxicity were selected to improve the eco-friendliness of completion and killing fluids.Finally,a systematic study was carried out to optimize the formulation and integrated technology in completion and killing fluid system.Field application has proved that these above-mentioned measures help ensure the safe operation of completion and workover under different reservoir conditions in Sichuan and Chongqing oil and gas fields.

CT降滤失酸是西南油气田分公司天然气研究院近年来研制的一种新型酸液体系。该体系以控制酸液滤失为主要特点 ,较好的解决了酸化施工时酸液的滤失。在现场施工中 ,无论是新井还是老井的重复酸化施工均取得了很好的施工效果。在已进行的 6口井施工中 ,施工有效率达 83% ,每天增加井口天然气产能近 30×10 4m3 。文章简要介绍了CT降滤失酸的性能及现场应用情况。

CT loss control acid is the newest acid izing fluid system. It is developed by the Research Institute of Natural Gas Technology, Southwest Oil and Gas Field Company of PetroChina. This article introduces the performance and field applications of the CT loss control acid. This acid have used in well TianDong 59,29,67, 84. Its effectiveness is high up to 75% .Well Tiandong 29,67,84 obtain increase productivity and a verage enhance production 29.73 x 104m3/d.

五百梯气田是西南油气田分公司上世纪90年代重点开发的低渗天然气田,其中6口井采用胶凝酸、前置液交替注入压裂酸化施工工艺实施深部改造后,使气井的天然气产能提高了90.45×104 m3/d,单井平均增产8.76倍,施工效果十分显著.本文介绍了该气田使用胶凝酸、前置液交替注入施工6口井的储层情况及室内评价确定的胶凝酸配方体系,并对该体系现场的应用效果进行了分析.

The primal problem in low temperature and shallow gas reservoirs is to overcome the break,the flowing back,and the damage of the fracturing fluids.This article introduces an organic-borate crosslinked guanidine gum fracturing fluids and theirs performance,and describes the application of these fracturing fluids in Baima-Songhua.Field tests in 4 wells show they are all successful.

The research work in the field of acidizing and fracturing have been done for about 30 years by RINGT,PetroChina Southwest Oil and Gasfield Company.It has developed CT series of acidizing and fracturing additives and their formulated fluid systems.This paper introduces the types and characteristics of these additives,the primary performances of the different formulated systems,and their application in the fields.