Wellbore Filtration Area Calculation Using LWD Directional Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for estimating reservoir production of fluid hydrocarbons are inaccurate due to assumptions about the wellbore's entire circumference being in contact with the reservoir, especially when the well is drilled parallel or at an angle to the formation dip, leading to incorrect filtration area calculations and production estimates.
Innovation Solution
A method and system that calculate the filtration area of a reservoir formation around a wellbore by obtaining directional measurements along the wellbore, selecting locations exposed to reservoir rock, and determining the filtration area at each measured depth interval, using logging while drilling data to account for partial contact with the reservoir.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the wellbore is drilled parallel or at an angle to the formation dip, then the wellbore crosses the formation boundary over a long section, but the assumption of hydrocarbon flow over the entire circumference leads to inaccurate production estimation
Solution Approach 1:
The wellbore is divided into multiple measured depth intervals, with each interval analyzed separately to determine the fraction of circumference in contact with reservoir rock. This segmentation allows accurate calculation of filtration area by summing contributions from individual intervals rather than assuming uniform contact along the entire wellbore.
Solution Approach 2:
Different sections of the wellbore are recognized to have different qualities of reservoir contact. The method calculates the fraction of circumference in contact with reservoir rock for each depth interval, acknowledging that contact varies locally along the wellbore rather than being uniform throughout.
2Measurement precision
If directional measurements are obtained for multiple measured depth intervals, then the actual contact area can be determined, but the data acquisition and processing complexity increases
Solution Approach 1:
The method uses directional measurements obtained during logging while drilling operations, which are already being performed for wellbore trajectory control. By repurposing this existing multi-functional data for filtration area calculation, the patent avoids requiring separate specialized measurement tools or procedures.
Solution Approach 2:
The patent uses an intermediary calculation approach where directional measurements are processed through a systematic method involving wellbore geometry parameters and formation dip angle relationships to derive the fraction of circumference in contact with reservoir rock, simplifying the overall measurement-to-result chain.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A set of directional measurements are obtained for multiple measured depth intervals along the length of a wellbore. Based on the directional measurement sets, and for each measurement set, the locations corresponding to a portion of the well exposed to the reservoir rock are selected. The filtration area of the reservoir formation is calculated based on the selected locations in each measured depth interval. The filtration area is presented for display and analysis.