Acidizing Composite Temporary Plugging

Technical Details

Tassel-shaped Rope Knot Temporary Plugging Agent

Item	Reservoir Temperature
Item	90℃~119℃	120℃~139℃	140~159℃	160℃及以上
Temperature Level	90℃	120℃	140℃	160℃
Material Density	1.08~1.25g/cm3	1.08~1.25g/cm3	1.08~1.25g/cm3	1.08~1.25g/cm3
Tail Length	30~50mm	30~50mm	30~50mm	30~50mm
Pressure Endurance	60℃30MPa≥1h	90℃30MPa≥1h	90℃30MPa≥1h	90℃30MPa≥1h
Dissolution Time	Dissolve ≤5% in fresh acid (20%HCl) within 1 hour at 60°C	Dissolve ≤5% in fresh acid (20%HCl) within 1 hour at 90°C	Dissolve ≤5% in fresh acid (20%HCl) within 1 hour at 90°C	Dissolve ≤5% in fresh acid (20%HCl) within 1 hour at 90°C
Dissolution Time	Dissolve ≥80% in spent acid (3%HCl) within 24 hours at 90°C	Dissolve ≥80% in spent acid (3%HCl) within 24 hours at 120°C	Dissolve ≥90% in spent acid (3%HCl) within 24 hours at 140°C	Dissolve ≥90% in spent acid (3%HCl) within 24 hours at 160°C
Plugging Rate	≥80%	≥80%	≥80%	≥80%

Technology Overview

To achieve uniform and refined stimulation, conventional carbonate reservoirs can also design tailored temporary plugging schemes based on different completion methods. For instance, in casing completion, using temporary plugging knots can effectively and precisely seal the perforations in long perforation sections, achieve interlayer and intralayer temporary plugging and diversion, and partially substitute mechanical layering. In open-hole completion, a composite temporary plugging scheme can be used to achieve temporary plugging within the fracture, thereby attaining refined and uniform stimulation.

①Casing Completion In-Fracture Temporary Plugging：

Use intelligent port plugs for flexible plugging. Since the working fluid of acid wells mostly consists of various acid systems with 15%~20% hydrochloric acid as the medium, the temporary plugging material requires high acid resistance and high temperature resistance properties.Depending on the number of perforations, use a dedicated ball thrower to launch 1~1.2 times the number of holes to be sealed, and customize the launch quantity, launch speed, and temporary plugging times as needed. By designing pumping displacement, homogeneous temporary plugging and diversion stimulation of different construction layers in the front, middle and rear sections of long construction sections can be achieved.

②Open-hole Completion In-Fracture Temporary Plugging：

Before pressurization, we calculate and simulate to obtain the radial extension length of the fracture before and after temporary plugging, and scientifically combine the temporary plugging material and form according to the fracture width and fracture width simulation value of the temporary plugging layer location, so as to accomplish efficient and accurate sealing. In the first stage, fibres adhere to the bottom and walls of the fracture; in the second stage, adhered fibres capture flowing particles and fill up the space between them, forming dispersed blocking zones;in the third stage, main channels are formed and continuously narrowed; in the fourth stage, the fracture is fully blocked. After the blocking process, particles are well distributed in the blocking area as a framework.