Perforations on Target
Ex ploration and production companies rely on new oriented perforating technology
to
optimiz e well productivity , minimiz e sand production and reduce overall completion costs in dif cult environments. Careful planning, technology selection and postjob evaluation are key s to an optimiz ed perforation strategy .
Kjell Berså s Morten Stenhaug Statoil
Bergen, Norw ay
Fokko Doornbosch Bjorn Langseth Stav anger, Norw ay
Helge Fimreite Hy dro
Bergen, Norw ay
Bob Parrott Rosharon, Tex as, USA
For help in preparation of this article, thanks to Wallace Pescarini, Al Salsman, George Spencer and Ian Walton, Rosharon, Texas, USA.
DepthLOG, eFire-CT, OCD (Orientation Con rmation Device), OrientXact, PowerJet, PowerJet Plus and PURE (Perforating for Ultimate Reservoir Exploitation) are marks of Schlumberger.
1. Morton N: “ Screening Out Sand,” BP Frontiers, issue 2 (December 2001): 18– 22.
2. Almaguer J, Manrique J, Wickramasuriya S, Habbtar A, Ló pez-de-Cá rdenas JE, May D, McNally AC and Sulbará n A: “ Orienting Perforations in the Right Direction,” Oil eld Rev iew 14, no. 1 (Spring 2002): 16– 31.
3. Sulbará n AL, Carbonell RS and Ló pez-de-Cá rdenas:
“ Oriented Perforating for Sand Prevention,” paper SPE 57954, presented at the SPE European Formation Damage Conference, The Hague, The Netherlands, May 31– June 1, 1999.
Sand production can create such serious prob- lems that a well costing millions of dollars to drill and complete becomes worthless. To protect their investment, exploration and production (E&P) companies today can orient well perforations. Oriented perforations can minimize sand production, improve productivity and reduce completion costs.
In 2001, a major oil producer reported 60% of
its worldwide production, around 2 million bar- rels [317,800 m3] of oil equivalent per day, was producing from fields requiring some level of sand management.1
evaluation can offer overall completion and pro- ductivity optimization.
In this article, we discuss the deleterious effects of misaligned perforations and then describe how careful application of inter- dependent technologies improves perforating results. Case histories illustrate recent advances in tubing-conveyed oriented perforating for optimizing initial well productivity and for inter- vention in underperforming wells.
Exacting Orientation Left unchecked, sand pro-
duction erodes downhole equipment, plugs the wellbore and ultimately chokes off fluid flow. Operators gather significant amounts of data relating to formation composition, bedding plane and stress orientation either through logging while drilling (LWD) or with wireline-conveyed logging techniques. These data, in conjunction with core analysis and offset-well performance, help operators establish a reservoir’s potential to produce sand.2
In reservoirs presenting anisotropic stress profiles and a likelihood of sand production, the integration of stress-analysis modeling, conveyance techniques, new advances in perfora- tion tool and charge design, and postfiring
In 1999, a major operator noted severe sand- production problems in the Eocene C reservoir in Lake Maracaibo, Venezuela. This reservoir is competent and consolidated but has high in-situ stresses resulting from a complex tectonic environment. By orienting perforations in the direction of maximum stress, the operator decreased the average sand produced from around 14 lbm/1,000 bbl [40 g/m3] of oil to an average of less than 2 lbm/1,000 bbl [6 g/m3], a reduction in produced sand of more than 85%.3 The first four wells with oriented perforations had 30% higher production rates than the fi eld average. This experience demonstrates that properly applied oriented perforating can signifi - cantly reduce sanding and enhance well
28
Oilfi eld Review
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76