Anton High Temperature Oil-based Test Fluid Technology help Tarim oilfield achieve cost reduction and efficiency increase
On December 15,2019, Keshen xxx-x well in Kuqa’s piedmont configuration，Xinjiang. Completion string was successfully put in place and interconnected by using Anton High Temperature Oil-based Test Fluid with the temperature of 185℃ and density of 1.90g/cm3. It is the first time that Anton 185℃ High Temperature Oil-based Test Fluid was used in Tarim. There is no Barite Sag in static condition at 185℃for 15 days. It can replace the ultra-micro water-based test fluid which was commonly used in high-temperature wells above 185℃ without the disadvantages of “large workload、long construction period、high cost and weakly for formation damage control”. It provides a effective technical support for the construction of 30 million tons of capacity and sustainable development of Tarim oilfield economically and efficiently in high temperature completion operation.
Kuqa's piedmont configuration is the main area for the 30-million-ton production project in the Tarim Oilfield. Most of the oil and gas reservoirs with Thick salt-paste layer, High-pressure brine layer and Fracture formation, TVD more than 6,500 meters and some wells exceed 8,000 meters. It is one of the most complicated formation for drilling in the world. This area has extremely high requirements for the completion fluid that there is no Barite Sag in static condition at 185 ℃ for 15 days, otherwise will fail to inject completion string and pump , severely it can lead to complex conditions such as failure of test tools, difficulty in setting or unsealing the packer, even affect the efficiency of oil and gas field development. Therefore, it is very urgent that the technical breakthrough of High-temperature Oil-based Test Fluid in Tarim oilfield.
To solve this problem, lots of mud companies and research institutes in the word began to research the high-temperature oil-based test fluid systems for several years, but there was no significant technological breakthrough. Before Keshen xxx-x well, only ultra-micro water-based test fluid could be used for high temperature wells above 185℃. Therefore, a research team had been established in Anton for the research and develop high-temperature oil-based test fluids at the end of 2017. After lots of investigation of the high-temperature oil-based drilling fluids status around the world, many high-temperature oil-based agents has been selected and evaluated roundly. Particularly, since the beginning of this year, A test technical regulations has been formulated, the best temperature-resistant materials have been evaluated. In July 2019, an oil-based test fluid system with the temperature of 180℃ and the density of 1.60g / cm³ had been developed. On the basis of it, optimizing weighting agent, an oil-based test fluid system with 185℃ and density of 1.90 g / cm³ had been developed successfully at the beginning of December 2019. Right now, Anton is working on 200℃ oil-based test fluid system to help higher temperature wells toachieve cost reduction and efficiency increase.