Production Optimization of High Temperature Liquid Hold Up Gas Well Using Capillary Surfactant Injection
Authors
S. A. Kalwar (Weatherford International Inc.) | A. Q. Awan (Weatherford International Inc.) | A. U. Rehman (Weatherford International Inc.) | H. S. Abbasi (Weatherford International Inc.)
Publisher
SPE - Society of Petroleum Engineers
Publication Date
March 6, 2017
Source
SPE Middle East Oil & Gas Show and Conference, 6-9 March, Manama, Kingdom of Bahrain
Paper ID
SPE-183676-MS
Abstract
Depletion of the reservoirs leads to a decrease in field production rate. Wells production rate continue to drop below the minimum critical velocity, at which point the liquid that was previously carried upward by the gas begins to fall back. The produced liquid accumulates in the well creating a static column of liquid, therefore creating a backpressure against formation pressure and reducing production until the well ceases production. Capillary Surfactant Injection (CSI) is installed on the wells to overcome the liquid loading symptom by generating foam, thereby reducing the surface tension, lowering the fluid density, and lowering critical rate.
This paper presents the comprehensive strategy of CSI application in high temperature gas well in Pakistan. Well 1A has been flowing under the critical conditions of liquid hold up with WGR of 82 bbl/MMscfd in high temperature (355 °F), deeper (11350 ft.), bigger tubing of size 5-1/2" and 7" Liner below the end of tubing along with compressor installed on it.
Based on nodal analysis, CSI was found the suitable Artificial Lift System (ALS) to deliquify this well. The procedure involved - laboratory analysis to monitor the temperature stability test of foamer (OMNIFOAM-HT) and defoamer (Alpha-2325) - scrutinizing the amount of foamer injected in the well to generate the foam - design of defoamer injection point and dosage to break the foam on surface - operational procedure - optimization mechanism - production enhancement and rapid payout time while executing CSI.
The lab results and field optimization showed OMNIFOAM worked successfully at high temperature and converted 350 - 400 barrels/day of formation water into foam at optimum injection rate of 4-5 gal/day. Defoamer injection (0.25-0.5 gal/day) was effectively carried from the injection point of corrosion inhibitor, around 150 feet upstream of compressor. CSI deployment significantly enhanced 15% rate of previous gas production and extended the life of the well to 4.0 years. If injection had been continued, the payback period was estimated to be 04 months. Based on these results, permanent deployment of CSI with renaissance wellhead system was recommended as promising solution for prolonging the life of well, sustaining its production in a short payout time and improving the reserve recovery.