This visualization compares planned versus actual oil well operations using two connected line charts. The top chart tracks operation timelines against dates, while the bottom chart displays cumulative costs over time. Using D3.js v5 with SVG rendering, the code employs d3.scaleBand, d3.scaleTime, and d3.scaleLinear to map operations, dates, and costs. Data comes from a hardcoded JavaScript array containing operation names, planned/real dates, and costs.