Research And Application Of High-density Curable Pre-liquid In Horizontal Wells In Western Sichuan

Horizontal wells has the advantage of a large contact area with the reservoir, small wellbore pressure, small fluctuations in resistance, etc. It has become the main type of production wells on the increase in western Sichuan. But it has been difficult to guarantee the quality of cementing, affecting the western area of exploration and development forward. Through the data of field research, we analyze the main factors affecting the western area of the horizontal well cementing quality:? Complex geological conditions, high-quality boreholes and borehole trajectory are difficult to obtain. ? Borehole unprepared, underground debris, mud cake and two mixed wrap residues accumulation, poor rheology of drilling fluid, seriously affecting operations of subsequent replacement and the interface bond performance. ?The poor chemical compatibility of drilling fluid systems and cement slurry. ?Anti-gas channeling cement slurry system is still difficult to meet the performance requirements of working fluid mixing and curing mud cake. The above factors influence is mainly manifested in:The drilling mud and cement slurry of being detained in whipstocking section, horizontal section is difficult to form a high consolidation strength, causing the poor cementing quality of Annulus two interface. For the above problems, the paper with the purpose of improving the cementing quality of horizontal wells in the western area, taking the measure of reducing the influence from the displacement efficiency and improve the cementing quality of mixing, mud cake cured, study the pre-solidifiable liquid technology to solve problems in western Sichuan horizontal well cementing quality.Pre-solidifiable liquid is an new technology based on the traditional pre-solidifiable liquid and solidifiable working fluid technology. It was added some material with potentially curing characteristics in traditional pre-solidifiable liquid system, with the activating agent, retarding agents, dispersing agents admixtures, admixture, so that it has isolation and anti-pollution action as well as strong comprehensive ability to cure. Research using GYW system, conducting research for the horizontal well cementing technology, investigate its flow capacity, thickening properties, chemical compatibility and curing properties. The results show:? GYW system has a wide adjustable density, temperature and pressure ranges.? Pre-solidifiable liquid with the properties of safe and adjustable multiviscosity, its flowability and chemical compatibility can meet the construction safety requirements by controlling the amount of activating agent, retarding agents and dispersants.? Pre-curable liquid with itself fast curing, high strength and long-term stability, high curing ability of mixing and interface cake, help to improve blended cement strength, and enhance the performance of the second interface cementation. This study developed a pre-solidifiable liquid technology and applied this technology on two horizontal well in western Sichuan. Logging results show, it got a substantial increase in cementing and isolation in the horizontal section and whip stocking segment.The laboratory study and field practice demonstrates the application feasibility and technical reliability of GYW pre-solidifiable liquid technology. It provides a sufficient basis of theoretical analysis for western Sichuan well cementing technology and accumulated valuable technical experience.