well json 2

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v3.min.js"></script>
  <script src="wells.js"></script>
  <script src="wells2.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    
    
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)

// Find range of depth column
    var depth_extent = d3.extent(wells, function(d) { return d.depth; })

// Create x-axis scale mapping dates -> pixels
    var xScale = d3.time.scale()
    	.range([0, 960])
    	.domain(time_extent);
    
    // Create y-axis scale mapping depth -> pixels
    var yScale = d3.scale.linear()  //scale y-axis to deepest well
    	.domain([0, maxDepth])
    	.range([chartHeight, 0])
    
    
    var xAxis = d3.svg.axis()
    	.scale(xScale)
    	.ticks(d3.time.years, 3);

var yAxis = d3.svg.axis()
    	.scale(yScale)
    	.orient("left");
    
    d3.select("svg")
    	.append("g")
    	.attr("class", "x axis")
    	.attr("transform", "translate(8,chartHeight)")
    	.call(xAxis);

d3.select("svg")
    	.append("g")
    	.attr("class", "y axis")
    	.attr("transform", "translate(79,29)")
    	.call(yAxis);

var circles = g.selectAll("circle")
    	.data(wells)
    
    
    circles.enter()
			.append("circle")
    	.attr("cx", function(d,i) { return  20 + i * 9})
    	.attr("cy", function(d,i) { return chartHeight - yScale(d.depth) }) // subtracting from chartHeight inverts the chart
    	.attr("r", 4)    
    	.on("mouseover", function(d) { console.log(d)})

</script>
</body>

https://d3js.org/d3.v3.min.js