Application of Horizontal Well Technology in Colombia N.F. Saavedra; N.F. Saavedra Ecopetrol Search for other works by this author on: This Site Google Scholar S.D. Joshi S.D. Joshi Joshi Technologies International Search for other works by this author on: This Site Google Scholar Paper presented at the SPE/CIM International Conference on Horizontal Well Technology, Calgary, Alberta, Canada, November 2000. Paper Number: SPE-65477-MS https://doi.org/10.2118/65477-MS Published: November 06 2000 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Saavedra, N.F., and S.D. Joshi. "Application of Horizontal Well Technology in Colombia." Paper presented at the SPE/CIM International Conference on Horizontal Well Technology, Calgary, Alberta, Canada, November 2000. doi: https://doi.org/10.2118/65477-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE/CIM International Conference on Horizontal Well Technology Search Advanced Search AbstractTo date, 20 horizontal wells have been drilled in Colombia, 16 in sandstone and 4 in carbonate reservoirs. In carbonate, the economical success rate is 50% but in sandstone it is 88%.In general, wells in Colombia are expensive. The vertical well cost varies from 2 million dollars to 11 million dollars, depending upon the reservoir depth. Horizontal well costs vary from 1.5 to 2.5 times the vertical well costs. Initially, most of the wells were completed with slotted liners. Now, new wells are completed with cemented and perforated liners to control water and gas production. The range of True Vertical Depth (TVD) is between 3000 and 16000 ft.This paper presents three brief field histories and the lessons learned to date. In cases where production is less than expected the principal causes are:–A horizontal well has commingled production from zones of high contrast in permeability, reducing considerably the producing length of a horizontal well.–Production of unwanted fluid such as water and gas. With slotted liner completion, it is not only difficult to identify gas and water producing zones but it is also difficult to isolate them effectively.–Geological uncertainty which results in drilling a well through a zone which is geologically different than expected.New horizontal wells are planned as short length wells in high permeability zones and long ones in low permeability zones. Also, re-entry wells are now used in mature reservoirs to reduce drilling costs.The method used to analyze the well performance is discussed in the paper. To determine the producing length, gamma ray analysis, log information, production tests and/or PLTs were used.A productivity analysis using analytical equations was also conducted to define if the well was damaged or had a small producing length. Then decline curve analysis was used to forecast rate and reserves and well production histories were matched for rates and cumulative production over time. Depending upon the problem, and considering feasibility and cost effectiveness, a corrective action was designed to improve well productivity.In summary, horizontal wells in Colombia have been successful and a large potential exists to drill many more wells.IntroductionThe history of horizontal wells in Colombia began in 1991with the attempt to drill the well Orito 1H, which did not reach the objective because of operational problems. In January of 1993 the well Chuchupa 14 was successfully completed in a gas reservoir with higher than expected production1. Then, in 1997 the well Guatiqu a 3H was drilled with some operational problems but with excellent productivity results in Apiay Reservoir1. From that another 18 wells have been drilled in different Colombian reservoirs.Out of 20 horizontal wells, 4 wells have been drilled in carbonate reservoirs and 16 have been drilled in sandstone reservoirs. From the 4 wells drilled in carbonate reservoirs one has been economically successful, one non-economical and two have too short a history to determine economics conclusively. The main reason for low oil production rates is the open hole completion, which provides an easy path for water production through natural fractures. In many Austin Chalk wells, high water production is also observed along with high oil rates. However, in Colombia, these horizontal wells are in heavy oil carbonate reservoirs. The high water rate typically reduces viscous oil production. Keywords: average permeability, information, sensitivity, spe ps-cim 65477, productivity analysis, porosity, permeability, reservoir surveillance, production history, application Subjects: Drilling Operations, Well & Reservoir Surveillance and Monitoring, Formation Evaluation & Management, Directional drilling This content is only available via PDF. 2000. SPE/PS-CIM International Conference on Horizontal Well Technology You can access this article if you purchase or spend a download.
