Plug-in Slim Bole Cementing Method In SuliGe Gas Field

SuLiGe gas field is a typical representative of our low porosity and low permeability gasreservoir, an area of about2×10~4km~2, the gas reservoir is rich in resources but development isdifficult, which is important blocks of the ChangQing gas field. For the effective developmentand reduce development costs to SuLiGe gas field, introduced a new model of slim-holedevelopment and related technology research. Slim-hole drilling led to the small gap betweenthe casing and the borehole wall, the cement sheath is thin, but to meet the subsequentconstruction operations such as fracturing, acidizing, water, mud flow resistance, high pressureconstruction, easy pressure drain formation, low displacement efficiency, presenting newchallenges for the slim hole cementing. To solve this problem, we introduce plug-in slim holecementing technology, it is cementing in the field of a special technology, in the case of smallgap wellbore cementing righting the technology is not yet cross the border, which caneffectively overcome or reduce the eccentricity of the casing and adherence problems,controlling the speed of the secondary on the back of the slurry and internal pressures ofwellbore to improve the displacement efficiency and ensure that the cementing quality.The grout of plug-in slim hole cementing technology have special requirements, requiringlong thickening time and stable performance. In addition, it must also be considered to apredetermined position. Therefore, the key aspect is the casing string interpolation process. Inthis process, due to the cement in thixotropic complex changes in the role of downholetemperature and pressure fields, which would bring the resistance of the annulus bottomholepressure changes. Friction loss and rheology also changes in the casing string into the processat all times. Therefore, to achieve high replacement cementing purposes of the overallpressure balance to achieve high-quality cementing, in-depth analysis and description of thisdynamic process are necessary.Through the analysis of slurry properties and stress analysis of plug-in casing string,establishing of the mathematical model between the various parameters, and using the C#computer language for programming simulation, combined with on-site construction instance,which do the comparative analysis. Finally improve the quality measures of plug-in slim holecementing, and gradually formed a set of plug-in slim hole cementing technology in SuLiGegas field.