Perpustakaan Digital ITB

As we know, the oil and gas industry is a high-risk industry. Various types of problems often occur in the oil and gas industry. One common problem is water production from reservoirs, known as water coning. This topic was chosen because water coning is a serious problem in the oil and gas industry that can disrupt and reduce well production. In addition, water production issues in a field can also affect well operation activities and have negative economic impacts. Therefore, it is important to evaluate water coning in a well. This study was conducted on well "W" in field "D". Field "D" is located in the South Natuna Sea, Block B. Field "D" was discovered in December 1989 and produced its first oil in October 1992. Well "W" is one of the wells in field "D" that began production in December 1992. One common problem in field "D" is the high water cut value, which is an indication of water coning problems. The objective of this study is to evaluate the water coning phenomenon in one of the wells in field "D", namely well "W", and determine the optimum flow rate for well "W" to operate economically. Several data were required for this study, including production data and well properties for well "W". There were several stages involved in this study. The first stage was to analyze the well's production history. The second stage continued by conducting Chan's diagnostic plot model screening. The third stage was calculating the critical flow rate using Meyer-Gardner, Schols, and Chaperon methods. The fourth stage was determining the breakthrough time using the Sobocinski-Cornelius method. From the results, an evaluation was conducted to determine whether well "W" was indicated to be experiencing water coning or not. The fifth stage was conducting reservoir simulation. From the reservoir simulation results, the most optimal flow rate for well "W" to produce economically was determined. Based on the production history analysis, it was apparent that well "W" had a decrease in oil production accompanied by an increase in water production and a significant increase in water cut value over time. This was one indication that there was a problem with water coning. Chan's diagnostic plot screening analysis also indicated that water coning problems occurred in this well. Based on the critical flow rate calculations using Meyer-Gardner, Schols, and Chaperon methods, it was found that the critical flow rate values from well "W" were 1198.18 STB/D, 1639.55 STB/D, and 413.2 STB/D, respectively. However, the actual flow rate for well "W" was 3703 STB/D, which exceeded the critical flow rate values calculated using all three methods. The breakthrough time for water was observed on the thirty-third day in well "W". Based on the production history analysis, Chan's diagnostic plot analysis, and critical flow rate calculations, it can be concluded that well "W" has a problem with water coning. Furthermore, the results of the reservoir simulation suggested that the recommended liquid rate for well "W" to operate economically was between 4000-5000 STB/D.