Horizontal Well

eP has a wide range of experience in horizontal well technologies related to the development of the company's software, consulting, and training services.

Well Test Design and Analysis for Horizontal Wells

eP has the foremost experts in well test analysis in the industry, with many years of practical experience in the design, analysis, and interpretation of well tests. eP's staff have undertaken several horizontal well projects. The consultancy expertise which eP can provide has been enhanced by the parallel development of the PanSystem well test analysis package which has included horizontal wells since 1990, and by giving many training courses all over the world. In addition, eP engineers have substantial practical experience in the acquisition of well test data, having worked for some of the leading data acquisition companies throughout the world and having supervised many tests.

Horizontal well test analysis frequently involves highly non-unique solutions in comparison to conventional vertical well test analysis. It is therefore necessary to approach the work with a good engineering-based understanding of the limitations of the well test data, and an appreciation of all the other sources of information that can be brought to bear on the problem.

Typical Activities

• Numerous consulting jobs covering horizontal well test analysis in sandstone and carbonate formations worldwide.
• Extensive software and engineering support through maintenance contracts for PanSystem and WellFlo.
• Courses and seminars on horizontal well analysis, run extensively worldwide since 1989.

Horizontal Well Stimulation and Completion Design

A unique feature of horizontal wells is their versatility and capability for being targeted to meet a specific application. This in turn has important implications for design of the well completion, which must be selected and optimized for the given application. Unlike the case of vertical wells, horizontal wells are not routinely cased and perforated. The result is that often formation petromechanical properties become dominant in well production behavior, and formation damage potential is magnified. eP offers the multi-disciplinary capability required to address the technical challenges which occur in completion design and stimulation operations. Staff within eP have extensive experience in core analysis, geomechanical analysis, completion practices, and well stimulation. eP also works closely with one of the most advanced geomechanical testing facilities in the United Kingdom.

Typical Activities

• Sand production prediction study for a UK Eocene reservoir. Analysis techniques included petrographic analysis, rock elastic properties determination, rock failure testing, and particle size analysis.
• Design of a horizontal well completion in an unconsolidated North Sea prospect. The project included selection of appropriate sand exclusion methodology and optimization using WellFlo to predict well performance as a function of component characteristics.
• Inclusion of horizontal well completion modules (stimulation, perforating, sand control) in eP production optimization training courses.

Horizontal Well Production Performance

The producing performance of a horizontal well is frequently anticipated to be greater than a comparable vertical well. However, there are many reasons why production may fall below expectations. eP provides a comprehensive approach to the determination of horizontal well productivity, based on an understanding of relevant reservoir description, well completion and stimulation, and vertical/artificial lift aspects of the well. This approach arises from the wide areas of expertise that eP's staff have in these areas. The WellFlo software incorporates much of this knowledge, and gives a fast means of examining key sensitivities.

Typical Activities

• Design of a high angle (85-90^o) well to maximize oil production while minimizing water coning. Study included use of well testing, nodal analysis, and simulation techniques. Well subsequently drilled and came in to predicted performance. (UK oil field).
• Design of a horizontal well in a carbonate reservoir, to maximize production through intersecting preferential fault direction. Design included artificial lift. Well came in to predicted performance. (UK oil field).
• Extensive software and engineering support through maintenance contracts for PanSystem and WellFlo.

Production Logging in Horizontal Wells

eP has considerable expertise in production logging. A total of 10 staff members have field experience in production logging, and half of these subsequently worked in computer-based production log interpretation. The company has presented production logging training courses for many years. More recently, the production logging software package PLOG has been obtained. Studies have been undertaken specifically to look at the response of tools in horizontal wells, where a whole range of unique problems arises.

Typical Activities

• Analysis and interpretation of 5 horizontal wells logged with conventional tools in Australia.
• Study of problems associated with horizontal well production logging, arising from well completion, fluid flow, and tool response effects. Included analysis of real examples of both conventional and new logging tools, in a variety of completion types and with different fluid types (International).
• Industry training in production logging: about 200 engineers have passed through schools run by eP in Edinburgh and in-house in a major operator in Aberdeen since 1990.

Reservoir Engineering Aspects of Horizontal Wells

Frequently, horizontal wells intersect multiple reservoir compartments, in a way that is analogous to a vertical well intersecting multiple layers. Just as eP was one of the first companies to offer multi-layer expertise in well testing and production, we quickly developed multi-compartment analysis methods. These have been applied in the analysis and prediction of performance in multi-well, multi-compartment reservoirs. The results of well inflow modeling, including completion and compartmentalization, can also be applied to improve reservoir simulation by better inflow definition. This is especially important if the aim of the study is prediction of water coning or gas cusping.

Typical Activities

• In produced gas fields, eP has analyzed well test and production data, including continuous surface and downhole pressure data, to estimate the volumetrics, reserves, fault transmissibility, and aspects of compartmentalization in the field. This type of study uses well test analysis, nodal analysis, and material balance techniques. eP has carried out several of these studies.