Practical methodology for interwell tracer applications

Abstract

Tracer technology has been used in the oil industry to investigate the fluid flow behavior into the reservoir. Using this technology is possible to obtain relevant data from the reservoir such as remaining oil accumulations, estimate volumetric sweep efficiency, define reservoir heterogeneities, identify flow channeling, and determine residual oil saturation (Sor).
 
 This technology has been one of the most useful tools for reservoir characterization for several decades. The tracer is injected in the injector well and then monitored in the producer wells through the tracer concentration measurements. Although many tracer studies have been documented for reservoir characterization, the available information and methodologies related to the design, implementation, and interpretation of tracer tests are limited or confidential.
 The goal of his article is to show a methodology for the design, execution, and interpretation of interwell tracer tests, which includes procedures for field implementation, sampling, and monitoring of these tests. Laboratory analysis using ultra-high-performance liquid chromatography is described in the experimental evaluation of tracer tests. Additionally, for a better understanding of the technology, examples of laboratory and field cases are presented.

Application of Isotope Tracer in Cross-Well Nanometre Tracer Testing

“…In order to understand the dynamic monitoring characteristics and heterogeneity characteristics of injection production wells in the monitoring area, judge the reservoir connectivity, and on this basis, systematically study the water breakthrough horizon, water breakthrough direction, and advancing speed of high water cut wells in the monitoring area, we should better understand the water drive law of injection production wells in the monitoring area and further describe the heterogeneity of well groups. Trace substance interwell nanometre tracer monitoring is carried out at the two horizons of Long 6 1 1 and Long 6 2 1 of well cluster 1 in the monitoring area. e fourthgeneration cross-well nanometre tracer monitoring technology is adopted in this monitoring.…”

“…By analyzing the background natural quantities of 7 elements in the produced water of the oil well corresponding to the water injection well, it is found that the background concentrations of Yb and Er tracers are low. Yb and Er are preliminarily selected to inject tracers into well cluster J1, and output indication of tracers Yb and Er in long 6 1 1 and long 1) [12]. Based on the abovementioned data and the background concentration of the produced elements in the water injection well, it is finally determined that the tracers injected into well cluster J1 are Yb and Er, and layered injection is adopted.…”

“…e J1 well cluster is located in the middle of the 6 1 1 basin and is geologically located in the middle and west of the Northern Shaanxi Slope. e average effective thickness of a single well of the Triassic long 6 1 1 layer, the main oil layer in the monitoring area, is 13.5 m, and the effective permeability is 2.5 × 10 − 3 μm 2 ; the average effective thickness of a single well in the long 6 1 1 formation is 16.8m, and the effective permeability is 2.78 × 10 − 3 μm 2 . e long 6 reservoir in well block J is a moderately strong heterogeneous reservoir [15].…”

“…Since the 1950s, oil field cross-well tracing technology has experienced great development in many countries in the world, from simple to deep, from qualitative interpretation to quantitative interpretation. The nanometre tracer selection, mineral construction, sampling analysis, and interpretation methods have been improved qualitatively [ 1 ]. The basic principle of interwell nanometre tracer test technology is to design the test scheme, select and prepare appropriate tracers by referring to the relevant dynamic and static data of the test well group, add tracers to the injection wells of the test well group, take samples and prepare samples in the surrounding production wells according to the established sampling system, conduct nanometre tracer analysis in the laboratory, and obtain the nanometre tracer content in the samples, as shown in Figure 1 .…”

“…Since the 1950s, oil eld cross-well tracing technology has experienced great development in many countries in the world, from simple to deep, from qualitative interpretation to quantitative interpretation. e nanometre tracer selection, mineral construction, sampling analysis, and interpretation methods have been improved qualitatively [1].…”