Research On Narrow Gap Cementing Technology In Extra-deep Of Oil And Gas Field Of ShunBei

Diabase intrusive body was developed in the ordovician of shunbei oil and gas field.The collapse stress of the diabase was high,and the 139.7mm casing in the hole of 165.1mm was required to be used for the special seal cementing operation,because the annulus gap is narrow,and the diabaseintrusive body contains high pressure brine layer.after cementing,saltwater channelingfrom the hanger external annulus restricted the subsequent development and production.Through the study ofhigh temperature toughening cement slurry system optimization,cement stone integrity analysis and small well cementing process optimization,optimized toconclusion the 150? of heat-resistant toughening slurry,the elastic modulus is 6.8GPa,the compressive strength is greater than 22MPa,the folding strength is greater than 4.5mpa,and the sealingwas still good after 12 times integrity evaluation of the alternating pressure between 15 and 50MPa was performed;The evaluation device of the cement integrity of narrow gap is developed.The internal cylinder can automatically apply the alternating pressure load,which can visual representation the ability of theannulus cement sealing;TO optimize and improvemente the ultra-deep narrow gap cementing process,formed the cementing support measures,ensured the exploration and development of shunbei oil and gas field.In this paper,technical innovation is carried out in the evaluation method of narrow gap cement ring integrity and toughening cement slurry system,the main research route is as follows:? Through the evaluation and selection of elastic material,concluded thehigh compressive strength and low modulus of elasticity of toughening slurry system,the thin cement ring can still be subjected to the large wellbore alternating load,which can effectively seal the annulus in the long term.?According to the parameters of narrow gap cementing in shunbei oil and gas field,designed the cement ring integrity evaluation device,and the internal cylinder can automatically apply the alternating pressure load,which can directly evaluate the integrity of the cement ring.?By optimizing the design of the spacer fluid,construction displacement,control the water layer,centralizer placement,etc,and optimizing the technical measures for enhancing displacement efficiency of narrow-gap cementing wells to improve the ultra-deep and narrow gap cementing technology and form matching technologies to guide on-site construction.