A Case Study of a Mature Field Redevelopment Using Propped Hydraulic Fracturing

Abstract

This paper will detail how a mature oil field in the South Kalimantan region of Indonesia was revitalised by the use of hydraulic fracturing. The Tanjung Raya field is a complex, multilayered, mature oil field. This field was initially developed in the 1960's, with production peaking at over 55,000 bopd. By the mid 1990's, production had declined to less than 1,200 bopd. The introduction of a water flood increased production to a peak of 10,000 bopd, but this quickly declined at an average rate of circa 33% per year. With the introduction of a fracturing programme, based on treating existing and new wells, production has been maintained at a flat 7,000 bopd over the past two years. The hydraulic fracturing program has accounted for 80% of these significant production gains, adding more than 5.7 million barrels of recoverable reserves and extending the economic life of the field by more than 2.5 years. Hydraulic fracturing is a process that is relatively underutilised in the Asia-Pacific region, as compared to North America, Latin America and the Middle East. With a couple of recent noticeable exceptions, the technique is either not considered during field development and redevelopment, or it is used on a one-off, remedial basis. However, fracturing can be an integral part of well design, and an effective tool when the technique is applied systematically by practitioners who understand its capabilities; as demonstrated in the Tanjung Raya field. This paper will discuss how a significant increase in oil productivity from a mature field was attained with a very high propped fracture treatment success rate. It will also detail how the correct design of fracture treatments can enhance reservoir recovery rates, and fully utilise vertical wells as a low cost, effective alternative to horizontal wells, or to increase well spacing. The paper will also discuss the most significant issues of implementing such a program and how these issues were effectively dealt with in the Tanjung field. Introduction Description of Field The Tanjung structure is located in the northeastern Barito basin in the Southeast corner of Kalimantan (Indonesian Borneo), as illustrated in Figure 1. The structure is a large, NS to NNE-SSW oriented, asymmetric faulted anticline, bounded on the west and north by a high-angle major thrust-fault with about 1500m of throw. The approximate dimension of the Tanjung structure is 9 km long and 3 km wide. The field covers an area of about 4000 acres. The Tanjung structure is a very late stage Plio-Pleistocene and is originally a normally faulted structural low, with a thick development of Tanjung formation. During the late Miocene and Pliocene, the Barito basin was subjected to a major phase of compression, thrust faulting, anticlinal folding, and strike slip faulting. This tectonic activity created most of the present day structures in the Barito basin, including Tanjung (see Appendix 1 for structural maps, Figures 8, 9 and 10).

Hydraulic Fracturing Makes the Difference: New Life for Old Fields

“…• Project Management: One of the fundamental building blocks of an efficient and economic mature field redevelopment plan is the creation of an effective, decisive and authoritative project management team at the earliest possible opportunity (Burnstad et al, 2004;and Kiburz and Sullivan, 1995). • Project Management: One of the fundamental building blocks of an efficient and economic mature field redevelopment plan is the creation of an effective, decisive and authoritative project management team at the earliest possible opportunity (Burnstad et al, 2004;and Kiburz and Sullivan, 1995).…”

“…Case History 1 Burnstad et al (2004) describe how hydraulic fracturing was used to rejuvenate the Tanjung field in South Kalimantan, on the Indonesian part of the island of Borneo. This mature field has been producing since the early 1960s, when production from about 220 producing wells peaked at nearly 50,000 bopd.…”

Reuse of Flowback Water from Hydraulic Fracturing for Drilling Mud Preparation and Secondary Hydrocarbon Recovery

“…Only minimal flowback treatment is necessary to meet these criteria. Mature oil fields are often revitalised by the use of hydraulic fracturing [34,35] and hence the resulted flowback can be reused for oil recovery. As flowback contains different surfactants and polymers its reinjection could be considered as a chemical enhanced oil recovery (CEOR) method.…”

Synthesis and application of nonionic polyacrylamide with controlled molecular weight for fracturing in low permeability oil reservoirs

“…[1][2][3][4][5] In the hydraulic fracturing process, a fracturing fluid is injected through a wellbore and against the face of the formation at high pressures; subsequently, the formation is forced to crack and fracture. The whole process is completed within 3 h. The fracturing fluid usually carries a proppant, such as 20-40 mesh sand, ceramics, or glass beads, which is suspended in the fracturing fluid and is transported into the fracture.…”