Research On Drilling Fluid Technology Of Reservoir Protection In Ha’de Area

Due to the oil and gas reservoir were buried deep in the west area, Formation has the characteristics of high temperature and high pressure. So it’s has been using by polysulfide drilling fluid system during drilling. The system has the very outstanding advantages of rheological properties, adaptability, high temperature resistance,etc. But its performance in reservoir protection was very poor. While The stand or fall of reservoir protection work is related to the discovery of new oil and gas field,oil and gas well production and oil field the economic benefit, So improvement in the reservoir protection performance of polysulfide drilling fluid is very important.In order to reduce the damage by drilling fluid to oil and gas formation during drilling, The temporary technology for reservoir is usually selected and the key is that temporary plugging particle size reasonably matches the pore throat.The matching is difficult to grasp,thus affecting the reservoir protection. According to the drawback of traditional temporary plugging technology in application, the technology of mosaic agent-membrane agent synergistic interaction for reservoir protection was proposed. Mosaic agent dszd and membrane agent CMJ-1 and BST-D for reservoir protection were developed and selected based on the combination of traditional evaluation of drilling fluid and evaluation of sand core test piece. If they were compounded, the temporary blocking rate and the slicing core permeability recovery was more than 90%.Comparing with the traditional blocking technique, they were increased by 20-40%, showing good synergistic interaction temporary blocking effect and stronger adaptability to different pores, which can be used as a new drilling fluid system for formation protection.