关键词: 水平井, 筛管完井, 环空化学封隔器, 管外分段, 触变, 定向治理, 控水增油

Abstract: A number of horizontal wells are completed with screen liners in China. Annular space exists between the screen liner and well wall, leading to well damage once water invades into the wellbore. It is a world-class bottleneck to control water cut and increase oil production. Use of chemicals for isolation of the annular in the later period and directional treatment of water producing spots become an important technological research direction. However, the “gravity collapse” effect makes conventional materials unable to fill the horizontal annular. The two-step crosslinking isolation chemicals are difficult to be controlled on the site. Based on magnetic materials, a type of fluid was developed with high thixotropic and solidification capacity, namely annular chemical packer colloids for horizontal well. The structure can be rapidly restored within 10 to 15 seconds after thinned by shearing. It can completely fill the horizontal annular. Under the effect of temperature, the solidification system based on multi-function group will transition to a high-strength solid annular chemical packer (ACP) from the thixotropic fluid. Under the temperature of 45 to 130°C, the solidification time can be controlled within three to 12 hours, the pressure bearing capacity exceeds 20MPa and the ACP loading error is ±5 meters. The process is safe and reliable and able to meet the demand for later-period treatment of horizontal wells for different types of oil reservoirs. The pilot test in conducted for the first time in China. Currently, it has been used in more than 10 domestic oil and gas fields, becoming an effective technological measure to control water cut and increase oil production from horizontal wells completed with screen liners.

Key words: horizontal well, screen liner completion, annual chemical packer, annular isolation, thixotropic property, directional treatment, control water cut and increase oil production