A. H. Mithani, E. A. Rosland, M. Jamaludin, W. R. W Ismail, Maxwell Tommie Lajawi, I. H. A Salam
{"title":"马来西亚成熟海上油田储层变质:H2S的根本原因、缓解和管理","authors":"A. H. Mithani, E. A. Rosland, M. Jamaludin, W. R. W Ismail, Maxwell Tommie Lajawi, I. H. A Salam","doi":"10.4043/32141-ms","DOIUrl":null,"url":null,"abstract":"\n The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to close in (few already closed). Hence, the shut-in wells have to be brought on stream and an assessment of souring potential in the field has to be completed. This paper will share our experience in H2S mapping at reservoir-well-facilities modelling, history matching and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field.\n A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In first phase we performed the analysis on the historical development of H2S throughout the field and developed the concept for possible souring causes. In second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existence knowledge gap. In third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing etc.\n It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of Sulphur isotope as H2S concentration increases, d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulphate while formation water rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150ppm could be a technically feasible options to mitigate such higher concentration of H2S within allowable facilities limits of H2S.","PeriodicalId":391718,"journal":{"name":"Day 4 Thu, May 05, 2022","volume":"75 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Reservoir Souring in Mature Offshore Field Malaysia: Root Cause, Mitigation, and Management of H2S\",\"authors\":\"A. H. Mithani, E. A. Rosland, M. Jamaludin, W. R. W Ismail, Maxwell Tommie Lajawi, I. H. A Salam\",\"doi\":\"10.4043/32141-ms\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to close in (few already closed). Hence, the shut-in wells have to be brought on stream and an assessment of souring potential in the field has to be completed. This paper will share our experience in H2S mapping at reservoir-well-facilities modelling, history matching and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field.\\n A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In first phase we performed the analysis on the historical development of H2S throughout the field and developed the concept for possible souring causes. In second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existence knowledge gap. In third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing etc.\\n It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of Sulphur isotope as H2S concentration increases, d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulphate while formation water rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150ppm could be a technically feasible options to mitigate such higher concentration of H2S within allowable facilities limits of H2S.\",\"PeriodicalId\":391718,\"journal\":{\"name\":\"Day 4 Thu, May 05, 2022\",\"volume\":\"75 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-04-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Day 4 Thu, May 05, 2022\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4043/32141-ms\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Day 4 Thu, May 05, 2022","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4043/32141-ms","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Reservoir Souring in Mature Offshore Field Malaysia: Root Cause, Mitigation, and Management of H2S
The field under study is a mature brownfield with no H2S in the fluid stream (PVT) at the time of development. However, concentrations more than 1000 ppm were recorded recently causing wells to close in (few already closed). Hence, the shut-in wells have to be brought on stream and an assessment of souring potential in the field has to be completed. This paper will share our experience in H2S mapping at reservoir-well-facilities modelling, history matching and prediction of H2S. We will highlight the workflow adopted to find the root causes of souring via sampling and modelling approach since the H2S is measured throughout the field across all the reservoirs, including those undergoing waterflood. Moreover, various options that were studied through simulation will be discussed for mitigation and management of H2S within this field to safeguard the production, and thus recovery of the field.
A systematic phased approach is adopted to mitigate and manage the unwanted sour gas (H2S). In first phase we performed the analysis on the historical development of H2S throughout the field and developed the concept for possible souring causes. In second phase, we designed and conducted a comprehensive sampling and laboratory analysis program end-to-end to fill the existence knowledge gap. In third phase, we performed 3D dynamic reservoir souring modelling where we history matched the H2S and assessed the future potential via forecasting. Finally, we developed multiple mitigation scenarios ranging from nitrate injection, sulphate reducing unit, limiting the nutrient supply for microbe growth via water mixing etc.
It was evident that a) increased injection water contributed to souring wells, b) link between souring wells and nutrient availability, c) increased negative fractioning of Sulphur isotope as H2S concentration increases, d) and mesophilic SRBs detected in some souring wells. This evidence suggested that BSR is the predominant cause of souring. It was also seen based on water chemistry that injection water was rich in sulphate while formation water rich in volatile fatty acids. Results indicate that the nitrate injection (up to 200ppm) alone may not be an attractive option to mitigate the H2S within this field. However, the combination of SRU and nitrate injection of 150ppm could be a technically feasible options to mitigate such higher concentration of H2S within allowable facilities limits of H2S.