Horizontal Well Treating Method Using Annulus Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for treating horizontal wellbores are inefficient due to difficulties in delivering a substantial volume of treating solutions to the appropriate region under pressure, often requiring high pumping rates and involving time-consuming procedures with conventional jointed tubing.
Innovation Solution
A method utilizing a packer and perforated nipple with a check valve in the working string to create a sliding seal between the casing and working string, allowing treating fluids to be pumped through the annulus with minimal backflow, enabling continuous treatment of horizontal strata with reduced head loss and friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional jointed tubing is used to deliver treating solutions in horizontal wellbores, then the treating solutions can be delivered to the formation, but the procedure becomes time-consuming and inefficient due to repeated connection and disconnection of tubing joints
Solution Approach 1:
The working string is nested within the production casing, allowing the treating tool to be delivered through the existing wellbore infrastructure. This eliminates the need for external tubing connections and enables continuous treatment operations without repeated assembly and disassembly of jointed tubing sections.
Solution Approach 2:
The method enables continuous pumping of treating solutions through the working string without interruption for connection or disconnection operations. The working string remains in place throughout the treatment process, allowing uninterrupted fluid delivery to the formation and significantly improving treating efficiency.
2Loss of energy
If coiled tubing is used to deliver treating solutions, then continuous fluid delivery is possible, but friction losses increase considerably due to the entire length of tubing, reducing flow rate
Solution Approach 1:
The treating tool and working string are extracted from the coiled tubing configuration and replaced with a rigid working string that can be positioned directly at the treatment zone. This eliminates the friction losses associated with long lengths of coiled tubing while maintaining continuous fluid delivery capability.
Solution Approach 2:
The approach transitions from using the length of tubing as the delivery mechanism (coiled tubing) to using the radial annulus space between the working string and casing for fluid delivery. This dimensional change allows treating solutions to be pumped through the annulus, bypassing the friction constraints of long tubing lengths.
3Quantity of substance
If high pumping rates are used to deliver substantial volumes of treating solutions under pressure, then the treating requirements are met, but the system requires high energy input and creates significant pressure losses
Solution Approach 1:
The working string is positioned in advance with the treating tool at the desired treatment zone before pumping begins. This preliminary positioning eliminates the need for continuous high-pressure pumping to move the tool through the wellbore, allowing energy to be focused solely on delivering treating solutions at the target location.
Solution Approach 2:
The annulus between the working string and production casing serves as an intermediary fluid pathway. Treating solutions are pumped through this annular space, which provides a low-resistance flow path that reduces pressure losses and energy requirements compared to forcing high volumes through narrow tubing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for efficient and direct treatment of horizontal strata by maximizing the annulus area for fluid transfer, reducing head loss and enabling continuous pumping of high volumes of treating solutions into the formation, thus enhancing hydrocarbon production.
Implementation Method 1
a sliding seal between the packer and the casing
Implementation Method 2
a check valve above the perforated nipple in the working string to prevent flow of fluid upward in the working string
Implementation Method 3
The treating fluid or solution is pumped into the annulus through the perforated nipple
Data Source
AI summary
Method of treating, especially, horizontally deviated wellbores where various treating solutions such as, acids, slurries, proppants, fracturing fluids, flushing fluids, or sealants are transferred into an annulus formed by a casing in the well and a working string. The working string has a seal member providing a sliding seal with the casing, a perforated nipple above the seal, and a check valve above the perforated nipple for preventing back flow through the working string to the surface. The working string has a seal element at the wellhead to avoid treating solutions leaking from the annulus out the wellhead. Treating solution of the desired make-up is pumped into the annulus, through the perforated nipple, down the working string, along the horizontal deviated wellbore, then into the strata or formation through a dispersing tool for the particular treating solution. The method provides a decrease in head loss, and if the working string uses a solid rod of lesser diameter than the remainder of the working string the head loss is further minimized. The apertures in the perforated nipple may be selected according to the requirements of the treating solution being pumped into the formation.