The reservoir of the Harahatang oilfield is buried deep (6600~7000m). It is a typical ultra-deep oil and gas reservoir. It mainly uses three open and two wells. The production layer adopts the naked hole completion method to ensure the subsequent oil recovery and completion process. Normally, the technical casing needs to be scraped before the opening, and the residual cement block, cement ring, various salt crystals and sediments on the inner wall of the casing are removed. The traditional casing scraper has a larger outer diameter than the inner diameter of the casing under the action of the compression spring, and cannot be drilled into the well at the same time as the tools such as drilling and boring. Generally, the drill is first scraped. In order to reduce the number of times the drill string is taken down and improve the efficiency of the work, a variety of different operations can be completed in one downhole. In 2011, the Tarim Project Department of Tarim Oilfield proposed that our company will jointly develop with China Oil Energy Corporation. After three months of intensive research at the job site of our company, after deep understanding of the routine operation techniques and tools of the oilfield users, a new work string was proposed, which can be used with tools such as drill plugs, milling, and wells. At the same time, after entering the well, after drilling, milling, and through-hole drilling, the ball is pressed to open the scraper and then scraped, fully satisfying the needs of the oilfield users, greatly reducing the mining cost for the oilfield users, and ultra-deep wells such as the Harahatang oilfield. Successfully promoted the application in drilling and completion operations.

The new MFC drilling and scraping integrated operation pipe string is composed of tools such as centralizer, MFC hydraulic scraper and sliding sleeve switch. And has obtained national patents. Patent No.: 201220389571.5.

1) Drilling and scraping wall integration

Well X702-1, technical casing specification: 200.03×10.92mm×6599m, drilled to 6835m to complete the drill. According to the results of electric test interpretation, in order to block the bottom water, it was decided to fill the ash back to 6670m. After the ash injection construction, the cement plug surface is 6469m, and the centralizer +7 7/8 hydraulic scraper + sliding sleeve switch + PDC bit integrated pipe string is drilled and scraped. On October 24, 2013, the drill pipe and scraping wall integrated pipe string reached the depth of 6469.0m to find the plug surface, the plug was drilled to 6670.0m, the cycle was one week, the depth was 6485.0m, the ball was thrown, and the pressure was 32MPa to open the hydraulic scraper. The blade repeatedly scrapes the wall 3 times in the well section 6400~6580m, and the well is washed for one week. The drill is inspected, the scraper is fully opened, and the sliding sleeve switch is normally opened. After the test oil is transferred, the pipe is cut into the completion and reformed, and the acid pressure is reformed. The maximum pump pressure is 83.3 MPa, and the packer is well sealed.

2) Through-hole and scraping wall integration operations

Well X702, technical casing specification: 177.8×10.36mm×6594m, artificial bottom 6660.0m, inspection operation. On October 1st, 2013, the centralizer, hydraulic scraper + sliding sleeve switch + tri-cone bit were integrated into the well, scraping the wall, drilling down to 6660.0m, circulating for one week, starting from the well depth of 4500m, pitching, Press 32MPa to open the hydraulic scraper blade, drill the scraper to 6588.0m, and repeatedly scrape the wall 3 times for the well section 4900~5100m, cycle the well for one week, start the drill check, the scraper and the sliding sleeve switch open normally, later Into the hand sand control column, the packer position is 5004m, and the seal is good.

After successful field test, the hydraulic scraper was widely applied in ultra-deep wells such as Harahatang Oilfield. As of October 2018, nearly 1,000 wells have been applied, and the scraping effect is good, and the post-operation is normal.

The hydraulic scraper meets the requirements of drilling plug, through-hole cleaning, scraping wall cleaning, etc., reducing the drilling time from 1 to 2 times, shortening the working cycle per well for more than 24 hours, improving the working efficiency and achieving good economic benefits and society. benefit. The drill plug and the scraping wall integrated working pipe column are used to drill the cement plug 140m in a single well. The longest single well drill section is 524.0m, the maximum well depth is 7158.0, and the highest well bottom temperature is 168°C. After the hydraulic scraper scrapes the wall, the packer is normally sealed in the scraped wall section, and the packer is well sealed during the acid pressure retrofit construction, and the post-operation is normal.