LQ乳液亲油水泥浆研究与性能评价

采用油基钻井液钻井时井壁和套管上附有油膜，造成固井时环空界面的胶结强度低。为解决该问题，从改善水泥浆自身的亲油性出发，选择羧酸类不饱和油溶性软单体和芳香族不饱和烯烃类刚性单体作为亲油单体，采用乳液聚合法将亲油单体与亲水单体聚合，合成了具有两亲结构的、稳定性较好的LQ乳液，并优选稳定剂，形成了LQ乳液亲油水泥浆。水泥浆性能评价试验结果表明:该水泥浆的API滤失量小于50 mL，稠化时间在150~300 min范围内可调、48 h抗压强度达到18 MPa以上，符合现场固井要求；LQ乳液在水泥石内部及表面形成疏水亲油膜，其与油膜接触时会吸油膨胀，从而提高附有油膜环空界面的胶结强度。研究表明，LQ乳液亲油水泥浆的性能达到现场固井要求，能提高附有油膜的环空界面的胶结强度。 

The Study and Property Evaluation of a Lipophilic Cement Slurry With LQ Emulsion

Wells drilled by using oil-based drilling fluids may have thin oil films attached to the sidewall and the casing, so low a cementation strength may be expected on annular interfaces during cementing. To solve this problem, the lipophilic properties of cement slurries have been modified through polymerization of lipophilic monomers and hydrophilic monomers through emulsion polymerization to generate LQ emulsion with desirable properties. During the process, soft carboxylic monomers dissolvable in unsaturated oil and rigid unsaturated olefin monomers were used as lipophilic monomers. By adding optimal stabilizers, lipophilic cement slurries with LQ emulsion were generated. Test results show that the slurry has an API filtration loss of no more than 50 ml, an adjustable thickening time of 150-300 min. and compressive strengths over 18 MPa in 48 hours. All these properties can meet the requirements of field cementation operations. LQ emulsion can form hydrophobic and lipophilic film inside and on surface of the cement. When in contact with oil film, the hydrophobic and lipophilic film may absorb oil then expand. In this way, the cementation strength in annular interface with oil film can be enhanced effectively. Test results show the lipophilic cement slurry prepared from LQ emulsion can be used in field cementation operations to enhance cementation strength of annular interfaces with oil films attached.