Riyanto, Latief (PETRONAS Carigali Sdn Bhd) | Sidek, Sulaiman (PETRONAS Carigali Sdn Bhd) | Hugonet, Vincent (PETRONAS Carigali Sdn Bhd) | Yusuf, M Hafizi (PETRONAS Carigali Sdn Bhd) | Salleh, Nurfarah Izwana (PETRONAS Carigali Sdn Bhd) | Ambrose, Jonathan Luke (SMS Oilfield)
Many oil and gas fields have long been suffering from sand production due to either the absence or failure of primary well sand control. To avoid mobilizing costly work-over rig to pull out the tubing, operators have tried various thru-tubing remedial sand control. The well's condition such as sands accumulation and space constraints due to small inner diameter of tubing always make this remedial job challenging. It is not surprising that the results are not all satisfactory.
Among the industry-recognized remedial sand control, Stand Alone Screen (SAS) is the simplest and the cheapest method. Many SAS have been installed but most were failed with screen erosion as the main failure mechanism. Flowing high velocity fluid with sands wears out the screen fast making it impossible for the sands to bridge and to create formation sand pack around the screen.
Ceramic Sand Screen (CSS) technology which was recently introduced to the industry aims to address this erosion issue. Having more than ten times hardness of stainless steel, sintered silicon carbide ceramic material in CSS offers superior resistance to wear. The pilot was conducted by installing CSS in three (3) selected wells with sand production history. While waiting for acoustic sand monitoring installation, the wells were put on production with the same choke size and regular manual samplings were conducted to monitor the sand production.
The acoustic sand monitoring campaign began in November 2017. Sands production was carefully monitored during the process to determine the final choke size at which the wells would continuously produce. In the middle of the campaign due to adverse weather conditions, all non-essential personnel had to be abruptly demobilised from the field leaving acoustic sensors hooked-up to the respective flow line. This gave opportunity to have unplanned extended sand monitoring window.
Loss of Primary Containment (LOPCs) occurred in two CSS wells not long after that. In one the choke body was heavily eroded and the other well had a punched hole at the first elbow of the flowline. These incidents prompted full investigation to be conducted. This included pulling out the installed CSS and performed tear down analysis. Acoustic sand monitoring that just happened to be available in one of the wells proved to be critical in understanding the CSS failure.
The paper presents briefly on the CSS pilot project, the chronology of events until the incident, sands production trend from the acoustic sand monitoring. Using all available information, the paper provides details analysis on CSS failure mechanism.
Sidek, Sulaiman (PETRONAS Carigali Sdn. Bhd.) | Hui Lian, Kellen Goh (PETRONAS Carigali Sdn. Bhd.) | Ching, Yap Bee (PETRONAS Carigali Sdn. Bhd.) | Trjangganung, Kukuh (PETRONAS Carigali Sdn. Bhd.) | Madon, Bahrom (PETRONAS Carigali Sdn. Bhd.) | Yusop, Zainuddin (PETRONAS Carigali Sdn. Bhd.) | Gundemoni, Bhargava Ram (3M Technical Ceramics) | Jackson, Richard (3M Technical Ceramics) | Barth, Peter (3M Technical Ceramics)
This paper will present the first successful application of ceramic sand screen in Malaysia. Oil production from the field has a long history beginning with the first production in 1972. A great number of sand control methods have been tested and applied in the field. Production history has showed instances of sand production contributed by factors such as in-situ stress changes, increase in water production and cascading effect from production operation activities. A few wells completed with primary sand control equipment have failed and remedial action by metallic through tubing sand screen experiencing rapid wear, forcing the operator to control sand production by beaning down the wells and closely monitoring sand production at surface overtime. Worse still, some of the wells had to be closed-in. Hence ceramic sand screen was considered as remedial sand control due to its superior durability and resistance compared to metallic sand screen.
Sidek, Sulaiman (PETRONAS Carigali Sdn. Bhd.) | Idris, Khairul Nizam (PETRONAS Carigali Sdn. Bhd.) | Lin, Kellen Goh Hui (PETRONAS Carigali Sdn. Bhd.) | Liang, Tan Kok (PETRONAS Carigali Sdn. Bhd.) | Moustafa, Azam Moustafa Abdelaziz (PETRONAS Carigali Sdn. Bhd.) | Hwa, Jason Kok Chin (AppSmiths) | Zakaria, Mohd. Zulfadly (AppSmiths) | Kamaludin, Mohammad Faris (AppSmiths) | Peacock, Larry (AppSmiths) | Ting, Khong Kheng (Elsa Energy Sdn. Bhd.)
Production Surveillance is a key activity carried out by oil and gas operators in the quest to maximize production. In Malaysia, specifically the East Malaysia Region, most of the wells in production are operated with the assistance of gaslift. Gaslift is an artificial lift method which involves injecting high pressure gas from the casing to enter the tubing via gaslift valves. Gaslift often hides inefficiencies, however by monitoring the operating conditions at the surface, an engineer will be able to obtain some clues on the performance of a gaslifted well.
Before the introduction of CO2 tracer technology, the only method available to operators to determine if a gaslift valve is open or closed downhole is to run a Flowing Gradient Survey (FGS) in order to determine the pressures and temperatures of the fluids in the tubing. Using a FGS in a well involves certain risk as it requires well intervention by running electronic memory gauges either on wireline or slickline to acquire data from a flowing well. There are also times where a FGS survey is inconclusive if the well is surging and have large changes in the surface pressures.
Since this is the fisrt such application in the field, two gaslift wells were surveyed for pilot application. The CO2 tracer technology is very effective for quick and reliable determination of lift gas entry points in the well. The technology allows the operator to detect the operating lift depth, detect multiple points of injection and even detect tubing leaks. This technology can be used as an alternate to FGS for the following advantages: Minimum equipment hook-up and no need to shut-in or choke the well, thus minimize production deferment. No wireline tools introduced into the wellbore, thus eliminate well intervention risk. Suitable for wells where a FGS is not possible due to well slugging, significantly deviated or with downhole obstruction. Possible to run survey on dual string wells to determine the gaslift split factor of a dual completion Possible to determine exactly how much gas is injected through each injection point of a well
Minimum equipment hook-up and no need to shut-in or choke the well, thus minimize production deferment.
No wireline tools introduced into the wellbore, thus eliminate well intervention risk.
Suitable for wells where a FGS is not possible due to well slugging, significantly deviated or with downhole obstruction.
Possible to run survey on dual string wells to determine the gaslift split factor of a dual completion
Possible to determine exactly how much gas is injected through each injection point of a well
This paper will describe the project objectives, the well candidate selection criteria, explain the execution of the survey and interpretation of the results and the value gain from implementing the recommendations from the survey results.